Kerr Iain D, Sivakolundu Sivashankar, Li Zhenmei, Buchsbaum Jeffrey C, Knox Luke A, Kriwacki Richard, White Stephen W
Department of Structural Biology, St. Jude Children's Research Hospital, 332 N. Lauderdale Street, Memphis, TN 38105, USA.
J Biol Chem. 2007 Nov 23;282(47):34392-400. doi: 10.1074/jbc.M705900200. Epub 2007 Sep 17.
The uvsWXY system is implicated in the replication and repair of the bacteriophage T4 genome. Whereas the roles of the recombinase (UvsX) and the recombination mediator protein (UvsY) are known, the precise role of UvsW is unclear. Sequence analysis identifies UvsW as a member of the monomeric SF2 helicase superfamily that translocates nucleic acid substrates via the action of two RecA-like motor domains. Functional homologies to Escherichia coli RecG and biochemical analyses have shown that UvsW interacts with branched nucleic acid substrates, suggesting roles in recombination and the rescue of stalled replication forks. A sequencing error at the 3'-end of the uvsW gene has revealed a second, short open reading frame that encodes a protein of unknown function called UvsW.1. We have determined the crystal structure of UvsW to 2.7A and the NMR solution structure of UvsW.1. UvsW has a four-domain architecture with structural homology to the eukaryotic SF2 helicase, Rad54. A model of the UvsW-ssDNA complex identifies structural elements and conserved residues that may interact with nucleic acid substrates. The NMR solution structure of UvsW.1 reveals a dynamic four-helix bundle with homology to the structure-specific nucleic acid binding module of RecQ helicases.
uvsWXY系统与噬菌体T4基因组的复制和修复有关。虽然重组酶（UvsX）和重组介导蛋白（UvsY）的作用已为人所知，但UvsW的确切作用尚不清楚。序列分析表明UvsW是单体SF2解旋酶超家族的成员，它通过两个RecA样运动结构域的作用来转运核酸底物。与大肠杆菌RecG的功能同源性和生化分析表明，UvsW与分支核酸底物相互作用，提示其在重组和挽救停滞的复制叉中发挥作用。uvsW基因3'端的一个测序错误揭示了第二个短开放阅读框，它编码一种功能未知的蛋白质，称为UvsW.1。我们已确定UvsW的晶体结构分辨率为2.7埃以及UvsW.1的核磁共振溶液结构。UvsW具有四结构域结构，与真核生物SF2解旋酶Rad54具有结构同源性。UvsW-ssDNA复合物的模型确定了可能与核酸底物相互作用的结构元件和保守残基。UvsW.1的核磁共振溶液结构揭示了一个动态的四螺旋束，与RecQ解旋酶的结构特异性核酸结合模块具有同源性。
