On Feb 25, 2013, at 4:55 PM, Eric Pettersen wrote:
You could then select only those residues whose phi/psi angles are in a certain range by using the Render by Attribute tool, changing to its "Select" tab, and adjusting the vertical bars on the displayed histogram to the range you want and clicking OK. This will select such residues across the entire structure, but you can then restrict them back to just residue 20 with "sel sel & :20".
I was going like gangbusters until I got to this part. If you are already using commands, by far the easiest way to select residues with attributes in a certain range is to use a command. For example, to select all cysteines with phis between -45 and 45:
:cys/phi>=-45 and phi <=45
all residues with sequence number 20 and psi values between 0 and 90:
:20/psi>=0 and psi<=90
etc.
--Eric