[ccp4bb]: molecular replacement for Fab molecule

[Vineet Gaur]

Hi,
I'm trying to find a molecular replacement solution for a Fab molecule. Have tried a few models with AMoRe. None of them seem to have worked as yet. The best soln. till now has a correlation of 40 and a R factor of 45. I was told that this problem sometimes occurs because of variable elbow angles in the Fab molecules and consequent variable heavy and light chain domain interfaces. So I split my model in to 4 fragments - Light and heavy chains and each chain into variable and constant domains. Now used four models as input (to try n simulate a hetro-tetramer) in AMoRe but the program gets stuck at a stage with the following error message:
'fixed part coming from a  6 body traing output
orientations coming from a 6 body traing output
stop >>o2tndo << no solution selected
stop >> amore<< error in previous step'
would somebody please help me figure this out. Any suggestions to solve the Fab molecular replacement problem in general??
Thanks