PLP undergoes conformational changes during the course of an enzymatic reaction

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Ngo, HPT (Author) Other; Nuno M F S A Cerqueira (Author) Other; Jin Kwang Kim (Author) Other; Myoung Ki Hong (Author) Other; Pedro Alexandrino Fernandes (Author) FCUP; Maria Joao Ramos (Author) FCUP; Lin Woo Kang (Author) Other

Journal

Title: Acta Crystallographica Section D: Biological Crystallography

Vol. 70

Pages: 596-606

ISSN: 0907-4449

Publisher: Blackwell

Indexing

ISI Web of Knowledge - 21 Citations

Scopus - 22 Citations

Scientific classification

FOS: Natural sciences > Chemical sciences

Other information

Authenticus ID: P-009-792

DOI: 10.1107/s1399004713031283

Abstract (EN): 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 degrees to 52 degrees. 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11