Thanks Suda! Hi Bodvael, I would only add: (A) To get strand number, it is probably best to do what Suda suggested: if looking at the sequence, just count the strands (green boxes) from N to C, or if looking at the structure, follow the ribbon from N to C. It may help to rainbow-color the structure, which by default goes from blue at the C-term to red at the N-term (Tools... Depiction... Rainbow in the menu, or command rainbow. Currently in Chimera the strand numbering is not necessarily from N->C... they are numbered in order of appearance in the PDB SHEET records, and sometimes the order of the strands in a sheet is different from N->C order. Keeping that in mind, you could select strands by number (will be shown with green highlighting on the structure) with commands, for example: select :/ssId=1 & strand (B) After you show the whole protein sequence as Suda said, you can search for some string of residues by choosing "Edit... Find Subsequence" from the sequence window menu. 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