Active Site Binding and Catalytic Role of Bicarbonate in 1,4-Dihydroxy-2-naphthoyl Coenzyme A Synthases from Vitamin K Biosynthetic Pathways

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	Active Site Binding and Catalytic Role of Bicarbonate in 1,4-Dihydroxy-2-naphthoyl Coenzyme A Synthases from Vitamin K Biosynthetic Pathways
	Sun YR(孙月茹) ; Song HG(宋海刚) ; Li J(李洁) ; Jiang M(蒋敏) ; Li Y(李艳) ; Zhou JH(周佳海) ; Guo ZH(郭志宏)
刊名	Biochemistry
	2012
卷号	51 期号:22 页码:4580-4589
ISSN号	0006-2960
其他题名	维生素K生物合成途径中碳酸氢根离子在MenB活性位点结合和催化作用
通讯作者	周佳海 ; 郭志宏
英文摘要	1,4-Dihydroxy-2-naphthoyl coenzyme A (DHNA-CoA) synthase, or MenB, catalyzes a carbon-carbon bond formation reaction in the biosynthesis of both vitamin K1 and K2. Bicarbonate is crucial to the activity of a large subset of its orthologues but lacks a clearly defined structural and mechanistic role. Here we determine the crystal structure of the holoenzymes from Escherichia coli at 2.30 angstrom and Synechocystis sp. PCC6803 at 2.04 angstrom, in which the bicarbonate cofactor is bound to the enzyme active site at a position equivalent to that of the side chain carboxylate of an aspartate residue conserved among bicarbonate-insensitive DHNA-CoA synthases. Binding of the planar anion involves both nonspecific electrostatic attraction and specific hydrogen bonding and hydrophobic interactions. In the absence of bicarbonate, the anion binding site is occupied by a chloride ion or nitrate, an inhibitor directly competing with bicarbonate. These results provide a solid structural basis for the bicarbonate dependence of the enzymatic activity of type DHNA-CoA synthases. The unique location of the bicarbonate ion in relation to the expected position of the substrate a-proton in the enzyme's active site suggests a critical catalytic role for the anionic cofactor as a catalytic base in enolate formation.
学科主题	生命有机化学
收录类别	SCI
原文出处	http://dx.doi.org/10.1021/bi300486j
语种	英语
WOS记录号	WOS:000304783200020
公开日期	2013-08-23
内容类型	期刊论文
源URL	[http://202.127.28.38/handle/331003/28505]
专题	上海有机化学研究所_生命有机化学国家重点实验室
推荐引用方式 GB/T 7714	Sun YR,Song HG,Li J,et al. Active Site Binding and Catalytic Role of Bicarbonate in 1,4-Dihydroxy-2-naphthoyl Coenzyme A Synthases from Vitamin K Biosynthetic Pathways[J]. Biochemistry,2012,51(22):4580-4589.
APA	孙月茹.,宋海刚.,李洁.,蒋敏.,李艳.,...&郭志宏.(2012).Active Site Binding and Catalytic Role of Bicarbonate in 1,4-Dihydroxy-2-naphthoyl Coenzyme A Synthases from Vitamin K Biosynthetic Pathways.Biochemistry,51(22),4580-4589.
MLA	孙月茹,et al."Active Site Binding and Catalytic Role of Bicarbonate in 1,4-Dihydroxy-2-naphthoyl Coenzyme A Synthases from Vitamin K Biosynthetic Pathways".Biochemistry 51.22(2012):4580-4589.