prasun kumar wrote: > There is a PATCH for adding sulfide bridge among two sulfur atom in a > peptide.Can we use this concept for adding two residues of two different > peptides at a certain angle...........

See my previous reply at http://salilab.org/archives/modeller_usage/2008/msg00257.html regarding suitable patching. If you wanted to fix some angle, you could add an angle restraint or define the angle in the patch definition (top_heav.lib) and set the mean value for the angle in the parameter file (par.lib).

Ben Webb, Modeller Caretaker