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B6db references: 26426567

type Journal Article
authors Hirayama A, Miyanaga A, Kudo F, Eguchi T
title Mechanism-Based Trapping of the Quinonoid Intermediate by Using the K276R Mutant of PLP-Dependent 3-Aminobenzoate Synthase PctV in the Biosynthesis of Pactamycin
journal Chembiochem
Activity pctv
Family pctv
sel selected
ui 26426567
year (2015)
volume 16
number 17
pages 2484-90
keywords PLP-dependent enzymes; biosynthesis; natural products; pactamycin; quinonoid
abstract Mutational analysis of the pyridoxal 5'-phosphate (PLP)-dependent enzyme PctV was carried out to elucidate the multi-step reaction mechanism for the formation of 3-aminobenzoate (3-ABA) from 3-dehydroshikimate (3-DSA). Introduction of mutation K276R led to the accumulation of a quinonoid intermediate with an absorption maximum at 580 nm after the reaction of pyridoxamine 5'-phosphate (PMP) with 3-DSA. The chemical structure of this intermediate was supported by X-ray crystallographic analysis of the complex formed between the K276R mutant and the quinonoid intermediate. These results clearly show that a quinonoid intermediate is involved in the formation of 3-ABA. They also indicate that Lys276 (in the active site of PctV) plays multiple roles, including acid/base catalysis during the dehydration reaction of the quinonoid intermediate.
last changed 2018/10/04 13:51

B6db references