The structure of the unliganded form of the Escherichia coli cytoplasmic peptidyl-prolyl isomerase (ppiB gene product) in a new crystal form was determined by the molecular replacement method and refined to an R-factor of 16.1% at 2.1 A resolution. The enzyme crystallized in the orthorhombic C2221 space group with unit cell dimensions of a=44.7 A, b=68.2 A and c=102.0 A. Comparison with the reported structure of the enzyme complexed with the tripeptide substrate succinyl-Ala-Pro-Ala-p-nitroanilide revealed subtle changes that occur upon complex formation. There is evidence to suggest that two surface loops have significantly reduced mobility in the complexed structure.
Crystal structure of cytoplasmic Escherichia coli peptidyl-prolyl isomerase: evidence for decreased mobility of loops upon complexation.,Edwards KJ, Ollis DL, Dixon NE J Mol Biol. 1997 Aug 15;271(2):258-65. PMID:9268657
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.