Exploiting large non-isomorphous differences for phase determination of a G-segment invertase-DNA complex.

ABSTRACT: Crystals of the G-segment invertase in complex with a 37-base-pair asymmetric DNA duplex substrate had an unusually high solvent content of 88% and diffracted to a maximal resolution of about 5.0 Å. These crystals exhibited a high degree of non-isomorphism and anisotropy, which presented a serious challenge for structure determination by isomorphous replacement. Here, a procedure of cross-crystal averaging is described that uses large non-isomorphous crystallographic data with a priori information of an approximate molecular boundary as determined from a minimal amount of experimental phase information. Using this procedure, high-quality experimental phases were obtained that have enabled it to be shown that the conformation of the bound substrate DNA duplex significantly differs from thos

SUBMITTER: Ritacco CJ 

PROVIDER: S-EPMC3949525 | biostudies-literature | 2014 Mar

REPOSITORIES: biostudies-literature