[PyMOL] problem when fitting backbone atoms of 2 different molecule selections

[Raul M. G. <rau...@gm...>]

Hi,

I want to superimpose 2 equivalent subunits of 2 protein structures (the 
same protein complex, but different biological subunits) by executing 
the command on 0.99rc6 version:

fit (2o25_1.renamed and bb_chZ), (2O25 and bb_chB)

where 2o25_1 is the mobile molecule, bb_chZ is the backbone of the 
selected chain, 2O25 is the target molecule and bb_chB is the  backbone 
target selected chain.

But it doesn't work, I obtain:

ExecutiveRMS-Error: No atoms selected.


Am I doing something wrong? I saw someone with almost the same problem 
(fitting 2 structures) and the same error message, using the same pymol 
version, in the mail list,... is it a bug then?

Thanks so much,

Raul