Hi Jason, * Jason Vertrees <javer...@utmb.edu> [2004-04-14 22:55] wrote: > Master Users, > > I'm a bit new to PyMol and still trying to master selections. I've read > the documentation and played with quite a few macromolecules now and > still have some problems with selections. > > For example, I found a PDB online called 'pope.pdb' (a cool lipid > bilayer; http://moose.bio.ucalgary.ca/Downloads/) and simply wanted to > select all the hydrophobic tails and hydrophilic heads so that I may > apply different attributes to each. If I need to select the tails, > which in the PDB are labeled from C10 (or so) to C50 depending on the > molecule, can I use something like c10-c50 (experience tells me no) or > must I do c10+c11+c12...c50?
The latter is correct, unfortunately. You can certainly do a selection like: select tails1, r. pop & n. c17+c18+c19+c20+c21+c22+c23+c24+c25+c26+c27+c28+c29+c30+c31+ca1+ca2+c36 +c37+c38+c39+c40+c41+c42+c43+c44+c45+c46+c47+c48+c49+c50 (where I've wrapped the line) or you could do the shorter selection first: select heads, r. pop & n. c5+c6+c12+c13+c15+c32+c34+n4+o7+o9+o10+o11+o14+o16+o33+o35+p8+h1+h2+h3 and then do: select tails2, r. pop &! heads If you don't want to go to the trouble of picking every atom to see its name, just select one atom in the residue (ctrl-middle-click) and show the atom name labels for the residue (use the pkresi selection in the right menu and labels are under "L") > So, it comes down to: do you prefer the macro method or standard; and, > do you have any hints or tips for more accurate or powerful selections? > As an example, how could I select just the tails or just the heads in > the aforementioned pope.pdb file? I found clicking on each atom to add them to the "lb" selection as Michael suggests less simple, but then I type quickly! Cheers, Rob -- Robert L. Campbell, Ph.D. <r...@post.queensu.ca> Senior Research Associate phone: 613-533-6821 Dept. of Biochemistry, Queen's University, fax: 613-533-2497 Kingston, ON K7L 3N6 Canada http://adelie.biochem.queensu.ca/~rlc PGP Fingerprint: 9B49 3D3F A489 05DC B35C 8E33 F238 A8F5 F635 C0E2