Solution structure of hypothetical Nudix hydrolase DR0079 from extremely radiation-resistant Deinococcus radiodurans bacterium
Solution structure of hypothetical Nudix hydrolase DR0079 from extremely radiation-resistant Deinococcus radiodurans bacterium
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DOI：
10.1002/prot.20082
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发表时间：
2004-07-01
影响因子：
2.9
通讯作者：
Kennedy, MA
中科院分区：
文献类型：
--
作者：
Buchko, GW;Ni, SS;Kennedy, MA
利用基于核磁共振（NMR）的方法，包括残余偶极偶联约束，我们确定了假设的耐辐射球菌Nudix蛋白DR0079（171个残基，MW = 19.3 kDa）的溶液结构。该蛋白含有8条p -链和3条a-螺旋，它们被组织成3个亚结构域：n端β -sheet(1-34)，一个Nudix核心（35140）和一个c端螺旋-转-螺旋（141-171）。Nudix核心和c端螺旋-旋转-螺旋形成了Nudix家族共同的基本折叠，一个大的混合β片夹在a-螺旋之间。组成Nudix特征序列GX(5)EX(7) rexeexgu（其中U = 1、L或V， X =任意氨基酸）的残基包含在混合P-sheet表面的一个旋转-螺旋-旋转基序中。化学位移映射实验表明DR0079与Mg2+结合。旨在确定该蛋白生物学功能的实验表明，它不是I型异戊烯基二磷酸三角洲异构酶，也不结合α， β -亚甲基腺苷5'-三磷酸（AMPCPP）或鸟苷5-[β，- γ -亚胺]三磷酸（GMPPNP）。本文将DR0079的结构与其他已知的Nudix蛋白结构进行了比较，提出了一种潜在的底物结合表面，并讨论了其可能的生物学功能。(C) 2004 Wiley-Liss, Inc。
Using nuclear magnetic resonance (NMR) based methods, including residual dipolar coupling restraints, we have determined the solution structure of the hypothetical Deinococcus radiodurans Nudix protein DR0079 (171 residues, MW = 19.3 kDa). The protein contains eight P-strands and three a-helices organized into three subdomains: an N-terminal beta-sheet (1-34), a central Nudix core (35140), and a C-terminal helix-turn-helix (141-171). The Nudix core and the C-terminal helix-turn-helix form the fundamental fold common to the Nudix family, a large mixed beta-sheet sandwiched between a-helices. The residues that compose the signature Nudix sequence, GX(5)EX(7)REUXEEXGU (where U = 1, L, or V and X = any amino acid), are contained in a turn-helix-turn motif on the face of the mixed P-sheet. Chemical shift mapping experiments suggest that DR0079 binds Mg2+. Experiments designed to determine the biological function of the protein indicate that it is not a type I isopentenyl-diphosphate delta-isomerase and that it does not bind alpha,beta-methyleneadenosine 5'-triphosphate (AMPCPP) or guanosine 5-[beta,-gamma-imido]triphosphate (GMPPNP). In this article, the structure of DR0079 is compared to other known Nudix protein structures, a potential substrate-binding surface is proposed, and its possible biological function is discussed. (C) 2004 Wiley-Liss, Inc.