1kzl
From Proteopedia
Riboflavin Synthase from S.pombe bound to Carboxyethyllumazine
Overview
Riboflavin synthase catalyzes the disproportionation of 6,7-dimethyl-8-ribityllumazine affording riboflavin and 5-amino-6-ribitylamino-2,4(1H,3H)-pyrimidinedione. We have determined the structure of riboflavin synthase from Schizosaccharomyces pombe in complex with the substrate analog, 6-carboxyethyl-7-oxo-8-ribityllumazine at 2.1 A resolution. In contrast to the homotrimeric solution state of native riboflavin synthase, we found the enzyme to be monomeric in the crystal structure. Structural comparison of the riboflavin synthases of S. pombe and Escherichia coli suggests oligomer contact sites and delineates the catalytic site for dimerization of the substrate and subsequent fragmentation of the pentacyclic intermediate. The pentacyclic substrate dimer was modeled into the proposed active site, and its stereochemical features were determined. The model suggests that the substrate molecule at the C-terminal domain donates a four-carbon unit to the substrate molecule bound at the N-terminal domain of an adjacent subunit in the oligomer.
About this Structure
1KZL is a Single protein structure of sequence from Schizosaccharomyces pombe. Full crystallographic information is available from OCA.
Reference
Studies on the reaction mechanism of riboflavin synthase: X-ray crystal structure of a complex with 6-carboxyethyl-7-oxo-8-ribityllumazine., Gerhardt S, Schott AK, Kairies N, Cushman M, Illarionov B, Eisenreich W, Bacher A, Huber R, Steinbacher S, Fischer M, Structure. 2002 Oct;10(10):1371-81. PMID:12377123 Page seeded by OCA on Fri May 2 23:22:07 2008
