Dear PyMol users!

I'm looking for the possible way to change some backbone didedral values in my peptide and dont perturbe the secondary structure of the rest of the peptide.

E.g I have alpha-helix with sequence   xxxxx-S-T-G-xxxxx    I want to make turn motif in the STG tripeptide only by  changing dihedral of this amino acids. When I've tried make it by means of DYNOPLOT plugin the rest of the alpha helix was distorded.

Is there any possible ways to make this conversion ?