
Hello: Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number) ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE; The said residue are not among those not located in the experiment. I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me. Thanks for aid francesco pietra

Hi Francesco, Those A and B are "alternate location" identifiers, and they are part of standard PDB format. Now with higher-resolution structures, sometime more than one position can be identified in the density map, and this allows the depositors to report those multiple positions. These are described in the "Intro to PDB Format" in the Chimera tutorials <http://plato.cgl.ucsf.edu/chimera/docs/UsersGuide/tutorials/framepdbintro.ht...> .. as well as at the PDB website <http://www.wwpdb.org/documentation/format33/sect9.html#ATOM> In Chimera you can specify these on the command line as @[atoms].[altlocs] similar to the what we do for chains, :[residues].[chains] Examples: color red @.a - color all atoms with alternate location A red ~disp :42@.b - undisplay alternate location B atoms in residue 42 I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Sep 15, 2011, at 8:31 AM, Francesco Pietra wrote:
Hello:
Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number)
ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O
About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE;
The said residue are not among those not located in the experiment.
I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me.
Thanks for aid
francesco pietra
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

Hello Elaine; My addendum was sent before I could read your mail. I wonder whether you could answer the addendum by suggesting to delete alternate position or avoiding to carry out molecular mechanics with such coordinates. I intended to proceed with REDUCE. Thanks francesco On Thu, Sep 15, 2011 at 6:13 PM, Elaine Meng <meng@cgl.ucsf.edu> wrote:
Hi Francesco, Those A and B are "alternate location" identifiers, and they are part of standard PDB format. Now with higher-resolution structures, sometime more than one position can be identified in the density map, and this allows the depositors to report those multiple positions.
These are described in the "Intro to PDB Format" in the Chimera tutorials <http://plato.cgl.ucsf.edu/chimera/docs/UsersGuide/tutorials/framepdbintro.ht...> .. as well as at the PDB website <http://www.wwpdb.org/documentation/format33/sect9.html#ATOM>
In Chimera you can specify these on the command line as @[atoms].[altlocs] similar to the what we do for chains, :[residues].[chains]
Examples:
color red @.a - color all atoms with alternate location A red
~disp :42@.b - undisplay alternate location B atoms in residue 42
I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco
On Sep 15, 2011, at 8:31 AM, Francesco Pietra wrote:
Hello:
Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number)
ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O
About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE;
The said residue are not among those not located in the experiment.
I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me.
Thanks for aid
francesco pietra
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

Hi everyone, It is my experience with Chimera on a Macintosh computer that the alternate designation must be case-sensitive. In other words: ~disp :42@.b - will NOT undisplay alternate location B atoms in residue 42 ~disp :42@.B - will undisplay alternate location B atoms in residue 42 YMMV, Darrell Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62G, MSC 2135 Bethesda, MD 20892-2135 Office 301-402-0095 Mobile 301-758-3559 http://bioinformatics.niaid.nih.gov (Within NIH) http://exon.niaid.nih.gov (Public) Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. On 9/15/11 12:13 PM, "Elaine Meng" <meng@cgl.ucsf.edu> wrote:
Hi Francesco, Those A and B are "alternate location" identifiers, and they are part of standard PDB format. Now with higher-resolution structures, sometime more than one position can be identified in the density map, and this allows the depositors to report those multiple positions.
These are described in the "Intro to PDB Format" in the Chimera tutorials <http://plato.cgl.ucsf.edu/chimera/docs/UsersGuide/tutorials/framepdbintro .html> .. as well as at the PDB website <http://www.wwpdb.org/documentation/format33/sect9.html#ATOM>
In Chimera you can specify these on the command line as @[atoms].[altlocs] similar to the what we do for chains, :[residues].[chains]
Examples:
color red @.a - color all atoms with alternate location A red
~disp :42@.b - undisplay alternate location B atoms in residue 42
I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco
On Sep 15, 2011, at 8:31 AM, Francesco Pietra wrote:
Hello:
Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number)
ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O
About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE;
The said residue are not among those not located in the experiment.
I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me.
Thanks for aid
francesco pietra
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

Hmm, that's very puzzling to me -- I'm using a Mac now and I tested exactly that before replying! Elaine for example: open 2fma disp focus :170 ~disp @.b (or, ~disp :170@.b) On Sep 15, 2011, at 9:28 AM, Hurt, Darrell (NIH/NIAID) [E] wrote:
Hi everyone,
It is my experience with Chimera on a Macintosh computer that the alternate designation must be case-sensitive. In other words:
~disp :42@.b - will NOT undisplay alternate location B atoms in residue 42
~disp :42@.B - will undisplay alternate location B atoms in residue 42
YMMV, Darrell

At any event I am at Debian GNU-Linux. In the meantime I came across a possible solution that should work on both Linux and Darwin, although it does not take account of the occupancy values. Probably, however, in the case I am interested in, the occupancy values are not too dissimilar (have to check), otherwise the authors would have not published so many alternate locations. http://www.biopython.org/wiki/Remove_PDB_disordered_atoms francesco On Thu, Sep 15, 2011 at 6:35 PM, Elaine Meng <meng@cgl.ucsf.edu> wrote:
Hmm, that's very puzzling to me -- I'm using a Mac now and I tested exactly that before replying! Elaine
for example: open 2fma disp focus :170 ~disp @.b (or, ~disp :170@.b)
On Sep 15, 2011, at 9:28 AM, Hurt, Darrell (NIH/NIAID) [E] wrote:
Hi everyone,
It is my experience with Chimera on a Macintosh computer that the alternate designation must be case-sensitive. In other words:
~disp :42@.b - will NOT undisplay alternate location B atoms in residue 42
~disp :42@.B - will undisplay alternate location B atoms in residue 42
YMMV, Darrell

Hi Francesco, I'm sure the Python script will work for you. However, it should be easy enough to select the B alternative positions with "@.b" and then use "Actions > Atom/Bonds > delete" to wipe them out. Then save the new PDB file. This will do exactly the same thing as the script you identified and may be easier for you. If you want to consider occupancy values, you may have to manually inspect the PDB file yourself. But maybe Elaine can come up with a clever way to do that in Chimera... Best of luck! Darrell Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62G, MSC 2135 Bethesda, MD 20892-2135 Office 301-402-0095 Mobile 301-758-3559 http://bioinformatics.niaid.nih.gov (Within NIH) http://exon.niaid.nih.gov (Public) Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. On 9/15/11 12:54 PM, "Francesco Pietra" <chiendarret@gmail.com> wrote:
At any event I am at Debian GNU-Linux. In the meantime I came across a possible solution that should work on both Linux and Darwin, although it does not take account of the occupancy values. Probably, however, in the case I am interested in, the occupancy values are not too dissimilar (have to check), otherwise the authors would have not published so many alternate locations.
http://www.biopython.org/wiki/Remove_PDB_disordered_atoms
francesco
On Thu, Sep 15, 2011 at 6:35 PM, Elaine Meng <meng@cgl.ucsf.edu> wrote:
Hmm, that's very puzzling to me -- I'm using a Mac now and I tested exactly that before replying! Elaine
for example: open 2fma disp focus :170 ~disp @.b (or, ~disp :170@.b)
On Sep 15, 2011, at 9:28 AM, Hurt, Darrell (NIH/NIAID) [E] wrote:
Hi everyone,
It is my experience with Chimera on a Macintosh computer that the alternate designation must be case-sensitive. In other words:
~disp :42@.b - will NOT undisplay alternate location B atoms in residue 42
~disp :42@.B - will undisplay alternate location B atoms in residue 42
YMMV, Darrell
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

On Sep 15, 2011, at 10:11 AM, Hurt, Darrell (NIH/NIAID) [E] wrote:
I'm sure the Python script will work for you. However, it should be easy enough to select the B alternative positions with "@.b" and then use "Actions > Atom/Bonds > delete" to wipe them out. Then save the new PDB file. This will do exactly the same thing as the script you identified and may be easier for you.
If you want to consider occupancy values, you may have to manually inspect the PDB file yourself. But maybe Elaine can come up with a clever way to do that in Chimera...
You can use the Dock Prep tool (in Surface/Binding Analysis) to eliminate the lower-occupancy alt locs. Or for these 50/50 alt locs, to get down to just one of the two. --Eric Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu

Hi Elaine, I was using the Aqua version of Chimera for Mac when it happened to me in a training session. Doh! Of course, I just tried it again on that same system and it did work. Maybe I did something else wrong... Either way, it is important to know how to treat those pesky alternative positions! Thanks, Darrell Darrell Hurt, Ph.D. Section Head, Computational Biology Bioinformatics and Computational Biosciences Branch (BCBB) OCICB/OSMO/OD/NIAID/NIH 31 Center Drive, Room 3B62G, MSC 2135 Bethesda, MD 20892-2135 Office 301-402-0095 Mobile 301-758-3559 http://bioinformatics.niaid.nih.gov (Within NIH) http://exon.niaid.nih.gov (Public) Disclaimer: The information in this e-mail and any of its attachments is confidential and may contain sensitive information. It should not be used by anyone who is not the original intended recipient. If you have received this e-mail in error please inform the sender and delete it from your mailbox or any other storage devices. National Institute of Allergy and Infectious Diseases shall not accept liability for any statements made that are sender's own and not expressly made on behalf of the NIAID by one of its representatives. On 9/15/11 12:35 PM, "Elaine Meng" <meng@cgl.ucsf.edu> wrote:
Hmm, that's very puzzling to me -- I'm using a Mac now and I tested exactly that before replying! Elaine
for example: open 2fma disp focus :170 ~disp @.b (or, ~disp :170@.b)
On Sep 15, 2011, at 9:28 AM, Hurt, Darrell (NIH/NIAID) [E] wrote:
Hi everyone,
It is my experience with Chimera on a Macintosh computer that the alternate designation must be case-sensitive. In other words:
~disp :42@.b - will NOT undisplay alternate location B atoms in residue 42
~disp :42@.B - will undisplay alternate location B atoms in residue 42
YMMV, Darrell

Addendum: I am aware about "alternate positions", what I don't know is how to treat such a protein, or whether it should be better to abandon modeling it. I have no idea which alternate position should be better deleted. francesco pietra ---------- Forwarded message ---------- From: Francesco Pietra <chiendarret@gmail.com> Date: Thu, Sep 15, 2011 at 5:31 PM Subject: Double coordinates for same residue To: chimera <chimera-users@cgl.ucsf.edu> Hello: Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number) ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE; The said residue are not among those not located in the experiment. I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me. Thanks for aid francesco pietra

Well, that is a more philosophical question that you will have to decide for yourself. There are also occupancy values (the column after the coordinates). In many cases it is reasonable to just delete the alternate positions with the lower occupancies. In your example A and B are equally strong (both 0.50), so one possibility is to just use one set and delete the others. For example, to delete all alternate locations B: delete @.b Another possibility is to make multiple models using the different locations. A structure with alternate locations may often be quite high resolution and high quality, so my personal opinion is you wouldn't want to throw the whole structure away just because you aren't sure what to do with these data. Elaine On Sep 15, 2011, at 9:14 AM, Francesco Pietra wrote:
Addendum: I am aware about "alternate positions", what I don't know is how to treat such a protein, or whether it should be better to abandon modeling it. I have no idea which alternate position should be better deleted. francesco pietra
---------- Forwarded message ---------- From: Francesco Pietra <chiendarret@gmail.com> Date: Thu, Sep 15, 2011 at 5:31 PM Subject: Double coordinates for same residue To: chimera <chimera-users@cgl.ucsf.edu>
Hello:
Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number)
ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O
About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE;
The said residue are not among those not located in the experiment.
I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me.
Thanks for aid
francesco pietra
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users

On Thu, Sep 15, 2011 at 6:23 PM, Elaine Meng <meng@cgl.ucsf.edu> wrote:
Well, that is a more philosophical question that you will have to decide for yourself.
There are also occupancy values (the column after the coordinates). In many cases it is reasonable to just delete the alternate positions with the lower occupancies. In your example A and B are equally strong (both 0.50), so one possibility is to just use one set and delete the others. For example, to delete all alternate locations B:
delete @.b
Another possibility is to make multiple models using the different locations.
If there are no criteria of preference, when many residues present alternate atom locations, as in this case, the number of possible combinations should deter anyone from going on. I would like to see examples of classical MD carried out with proteins of such features. If one is interested in ligand paths inside the protein, alternate positions of side chains are not encouraging. 1.9A resolution is excellent work, which might mean that this set of coordinates is not what one can safely use for MD for that use, not to say if one is interested in energies. Perhaps the collection of reflections was not at low temp. francesco
A structure with alternate locations may often be quite high resolution and high quality, so my personal opinion is you wouldn't want to throw the whole structure away just because you aren't sure what to do with these data. Elaine
On Sep 15, 2011, at 9:14 AM, Francesco Pietra wrote:
Addendum: I am aware about "alternate positions", what I don't know is how to treat such a protein, or whether it should be better to abandon modeling it. I have no idea which alternate position should be better deleted. francesco pietra
---------- Forwarded message ---------- From: Francesco Pietra <chiendarret@gmail.com> Date: Thu, Sep 15, 2011 at 5:31 PM Subject: Double coordinates for same residue To: chimera <chimera-users@cgl.ucsf.edu>
Hello:
Surely a naive question: While beginning to treat a multichain, engineered protein - downloaded from PDB web (1.94 A resolution) - with Chimera, I noticed that many amino acids have such feature as GLU 252 below. Same for many SER, ILE, HIS (two imidazole rings for the same residue number)
ATOM 2022 N GLU A 252 15.171 -45.532 45.115 1.00 26.12 N ATOM 2023 CA AGLU A 252 14.023 -44.631 45.214 0.50 26.30 C ATOM 2024 CA BGLU A 252 14.048 -44.592 45.252 0.50 26.30 C ATOM 2025 C GLU A 252 13.983 -43.654 44.050 1.00 25.90 C ATOM 2026 O GLU A 252 12.894 -43.403 43.470 1.00 25.36 O ATOM 2027 CB AGLU A 252 13.974 -43.909 46.559 0.50 26.93 C ATOM 2028 CB BGLU A 252 14.170 -43.759 46.533 0.50 26.77 C ATOM 2029 CG AGLU A 252 13.283 -44.741 47.629 0.50 29.02 C ATOM 2030 CG BGLU A 252 12.874 -43.673 47.313 0.50 29.14 C ATOM 2031 CD AGLU A 252 14.088 -45.948 48.051 0.50 33.10 C ATOM 2032 CD BGLU A 252 12.806 -44.716 48.426 0.50 31.91 C ATOM 2033 OE1AGLU A 252 13.481 -47.014 48.330 0.50 34.82 O ATOM 2034 OE1BGLU A 252 13.394 -44.454 49.504 0.50 31.18 O ATOM 2035 OE2AGLU A 252 15.333 -45.828 48.101 0.50 35.49 O ATOM 2036 OE2BGLU A 252 12.162 -45.782 48.231 0.50 33.14 O ATOM 2037 N GLU A 253 15.141 -43.133 43.683 1.00 24.58 N ATOM 2038 CA GLU A 253 15.225 -42.212 42.559 1.00 25.11 C ATOM 2039 C GLU A 253 14.838 -42.941 41.242 1.00 23.83 C ATOM 2040 O GLU A 253 14.142 -42.383 40.374 1.00 23.54 O ATOM 2041 CB GLU A 253 16.637 -41.603 42.476 1.00 26.18 C ATOM 2042 CG GLU A 253 17.033 -40.722 43.697 1.00 30.81 C ATOM 2043 CD GLU A 253 17.635 -41.491 44.915 1.00 36.16 C ATOM 2044 OE1 GLU A 253 17.540 -42.742 45.032 1.00 35.80 O ATOM 2045 OE2 GLU A 253 18.198 -40.809 45.801 1.00 40.87 O
About the protein: SOURCE 2 ORGANISM_SCIENTIFIC: PSEUDOMONAS MENDOCINA; SOURCE 3 ORGANISM_TAXID: 300; SOURCE 4 GENE: TMOA; SOURCE 5 EXPRESSION_SYSTEM: ESCHERICHIA COLI; SOURCE 6 EXPRESSION_SYSTEM_TAXID: 562; SOURCE 7 EXPRESSION_SYSTEM_STRAIN: BL21; SOURCE 8 EXPRESSION_SYSTEM_VECTOR_TYPE: PLASMID; SOURCE 9 EXPRESSION_SYSTEM_PLASMID: P58KABE;
The said residue are not among those not located in the experiment.
I am interested in channels, pores and so on in the protein, so that the above issue is of most concern for me.
Thanks for aid
francesco pietra
_______________________________________________ Chimera-users mailing list Chimera-users@cgl.ucsf.edu http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users
participants (4)
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Elaine Meng
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Eric Pettersen
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Francesco Pietra
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Hurt, Darrell (NIH/NIAID) [E]