Hi Pavel, It has been a while since our last communication. I'm writing to you to in an attempt to exploit once used possibility to refine structure with your help in Phenix while I'm not a Phenix subscriber. The structure is at low 3.o A resolution and includes antibody Fab fragment and an Antigen. My primary interest is to try SA option in Phenix and to build missing several residues in chains C and D both belonging to antigen. In addition, there are 2 complexes per a.u., i.e. I have 2 Fab-Antigen complexes in a.u. Each Fab consists of two chains: light and heavy. So, there are 6 protein chains in the a.u. Will you be kind enough to give it a try in Phenix with SA option active? Thank you. _______ Vaheh To the extent this electronic communication or any of its attachments contain information that is not in the public domain, such information is considered by MedImmune to be confidential and proprietary. This communication is expected to be read and/or used only by the individual(s) for whom it is intended. If you have received this electronic communication in error, please reply to the sender advising of the error in transmission and delete the original message and any accompanying documents from your system immediately, without copying, reviewing or otherwise using them for any purpose. Thank you for your cooperation.