From: Ivan Gregoretti (
Date: Sat Feb 22 2014 - 17:29:35 CST

When running psfgen I get two complains for the "A" chain of 3GRW:

unknown residue type NAG
unknown residue type HOH
Info: generating structure...psfgen) unknown residue type NAG
ERROR: failed on end of segment
MOLECULE DESTROYED BY FATAL ERROR! Use resetpsf to start over.

Could anybody point me to a document to read and figure out a solution?

Thank you,


Ivan Gregoretti, PhD