Activities | Families | Sequences | Fold types | References | Help
B6db references: 24531493

type Journal Article
authors Ngo HP, Cerqueira NM, Kim JK, Hong MK, Fernandes PA, Ramos MJ3, Kang LW
title PLP undergoes conformational changes during the course of an enzymatic reaction
journal Acta Crystallogr D Biol Crystallogr
sel selected
ui 24531493
year (2014)
volume 70
number 2
pages 596-606
keywords PLP-dependent enzymes; Xanthomonas oryzae pv. oryzae; XometC; cofactor conformational change; cofactor-based catalysis; pyridoxal 5′-phosphate
abstract Numerous enzymes, such as the pyridoxal 5'-phosphate (PLP)-dependent enzymes, require cofactors for their activities. Using X-ray crystallography, structural snapshots of the L-serine dehydratase catalytic reaction of a bacterial PLP-dependent enzyme were determined. In the structures, the dihedral angle between the pyridine ring and the Schiff-base linkage of PLP varied from 18 to 52. It is proposed that the organic cofactor PLP directly catalyzes reactions by active conformational changes, and the novel catalytic mechanism involving the PLP cofactor was confirmed by high-level quantum-mechanical calculations. The conformational change was essential for nucleophilic attack of the substrate on PLP, for concerted proton transfer from the substrate to the protein and for directing carbanion formation of the substrate. Over the whole catalytic cycle, the organic cofactor catalyzes a series of reactions, like the enzyme. The conformational change of the PLP cofactor in catalysis serves as a starting point for identifying the previously unknown catalytic roles of organic cofactors.
last changed 2019/05/20 10:36

B6db references