[PyMOL] L->D amino acid conversion using pymol

[Heinz-Uwe H. <uwe...@tg...>]

Gents,

I want to try to visualize a retro-enantio Conotoxin peptide (reverse=20
sequence, all D-amino acids, sculpting) and visually compare surface=20
charge to its normal L-amino acid counterpart using Pymol. I use Pymol=20=

0.93 (fink compiled) on a Powerbook G4/667 with three-button mouse.

Mutating residues using the mutation wizard works fine, but I get an=20
error upon L->D conversion. Using the mouse, I understand from the=20
reference manual the following procedure:

Invert
NOTE
The invert function is usually bound to CTRL=E2=88=92E in editing mode.
The default selections are (lb) and (rb), meaning that you can pick
the atom to invert with CTRL=E2=88=92middle click and then pick the
stationary atoms with CTRL=E2=88=92SHIFT/left=E2=88=92click and =
CTRL=E2=88=92SHIFT/right=E2=88=92
click, then hit CTRL=E2=88=92E to invert the atom.

After correctly following this mouse-procedure selecting c-alpha and=20
nitrogen, an error-message says: invert error: couldn't find basis for=20=

inversion. The same applies when trying via  command line (example for=20=

residue one):

PyMOL> edit 1/ca
PyMOL> invert 1/n, 1/ca
invert error: couldn't find basis for inversion

What am I doing wrong ?

Kind regards
Uwe Hobohm
Heinz-Uwe Hobohm=