sorry that you didnít get a reply on this question so far. Itís a good question, not native at all. This is a perfect task for sculpting in PyMOL. You should fix the atoms which should not move, and limit the terms to bond length and angles (no torsion or VDW).
The steps to do are best described in this short screencast:
Hope that helps.
On 01 Nov 2013, at 10:29, ccp4 pymol <firstname.lastname@example.org> wrote:
> Hi to everyone,
> My apologies if the question is to naive. I was wondering if there was an easier way to flip the puckering of ribose from endo to exo conformations at 2' and 3' positions in pymol.
> Thank you
> Best wishes