Hi CCP4 community! I have constructed a homology model of a deletion variant of a protein whose structure has already been solved. These deletions are 3-4 amino acid in length and are in a loop that connects two helices. The model structures look good with respect to bond lengths in the aforementioned loop region but the bond angles (especially Phi and Psi) are very distorted. Ramachandran plot suggests the same and some of the amino acids flanking the loop are now in the disallowed region. I thought one way to avoid this is to delete one amino acid at a time and construct the model and use the previous model as the template to construct the next model. This is not working very well in fixing the wrong angles.
I was wondering if 1) Anybody out there knows good homology modeling software. I used SWISS model and CPH model to create my models. I have heard about prime but right now am waiting to get the software . 2) Is there a way I can fix the angles if I perform an energy minimization of the model. Suggestions are appreciated. Thanks, Anagha.
