Stereochemistry of C-3 deoxygenation of sugar nucleosides: formation of pentopyranine C from [3-2H]-D-glucose by Streptomyces griseochromogenes
作者:Steven J. Gould、Jincan Guo
DOI:10.1021/ja00052a014
日期:1992.12
Cytosylglucuronicacid (CGA) has previously been shown to be the first intermediate in the biosynthesis of the antibiotic blasticidinS (BS), produced by Streptomycesgriseochromogenes. Addition of aminooxyacetic acid (AOAA), an inhibitor of pyridoxal phosphate/pyridoxamine phsophate-dependent transminases, to S. griseochromogenes fermentations led to substantial accumulations of CGA and pentopyranine
A mechanistic study of the non-oxidative decarboxylation catalyzed by the radical S-adenosyl-<scp>l</scp>-methionine enzyme BlsE involved in blasticidin S biosynthesis
Decarboxylation is a fundamentally important reaction in biology and involves highly diverse mechanisms. Here we report a mechanistic study of the non-oxidative decarboxylation catalyzed by BlsE, a radical S-adenosyl-L-methionine (SAM) enzyme involved in blasticidin S biosynthesis. Through a series of biochemical analysis with isotopically labeled reagents, we show that the BlsE-catalyzed reaction
Radical <i>S</i>-Adenosyl Methionine Enzyme BlsE Catalyzes a Radical-Mediated 1,2-Diol Dehydration during the Biosynthesis of Blasticidin S
作者:Yu-Hsuan Lee、Xueli Hou、Ridao Chen、Jianqiang Feng、Xiao Liu、Mark W. Ruszczycky、Jin-Ming Gao、Binju Wang、Jiahai Zhou、Hung-wen Liu
DOI:10.1021/jacs.1c12010
日期:2022.3.16
instead a lyase that catalyzes the dehydration of cytosylglucuronicacid (CGA) to form cytosyl-4′-keto-3′-deoxy-d-glucuronic acid, which can rapidly decarboxylate nonenzymatically in vitro. Analysis of substrate isotopologs, fluorinated analogues, as well as computational models based on X-ray crystal structures of the BlsE·SAM (2.09 Å) and BlsE·SAM·CGA (2.62 Å) complexes suggests that BlsE catalysis
由于自由基S-腺苷甲硫氨酸 (SAM) 酶 BlsE的参与,杀稻瘟菌素 S 的生物合成引起了人们的关注。最初将 BlsE 指定为自由基介导的氧化还原中性脱羧酶是不寻常的,因为该反应似乎没有生物合成目的,需要通过随后的羧化步骤来逆转。此外,除了 BlsE 之外,迄今为止报道的所有其他自由基 SAM 脱羧酶本质上都是氧化的。然而,对 BlsE 反应的仔细分析表明,BlsE 不是脱羧酶,而是一种裂解酶,它催化 cytosylglucuronic acid (CGA) 脱水形成 cytosyl-4'-keto-3'-deoxy- d -glucuronic acid,其可以在体外快速非酶脱羧. 对底物同位素、氟化类似物以及基于 BlsE·SAM (2.09 Å) 和 BlsE·SAM·CGA (2.62 Å) 配合物的 X 射线晶体结构的计算模型的分析表明,BlsE 催化可能通过直接消除来自 CGA