Single-stranded DNA binding properties of the UvsX recombinase of bacteriophage T4: Binding parameters and effects of nucleotides
Single-stranded DNA binding properties of the UvsX recombinase of bacteriophage T4: Binding parameters and effects of nucleotides
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DOI：
10.1006/jmbi.1998.2124
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发表时间：
1998-11-06
影响因子：
5.6
通讯作者：
Morrical, SW
中科院分区：
文献类型：
--
作者：
Ando, RA;Morrical, SW
噬菌体T4为DNA代谢的生物化学和遗传学提供了重要的模型。噬菌体编码的蛋白进行T4 DNA复制、修复和重组的所有必要步骤。这三个过程的中心是T4 UvsX蛋白，其是以大肠杆菌RecA蛋白为代表的丝状、ATP依赖性的一般重组酶类的成员。与RecA类似，UvsX在单链（ss）DNA上形成突触前丝，其是重组中的必需核蛋白中间体。T4突触前丝的方面进行了探讨，通过定量表征的UvsX-ssDNA的相互作用，使用etheno-derivitized单链DNA分子，DNA，其荧光增强UvsX结合。使用该模型晶格的研究表明，当UvsX与具有等于四个核苷酸残基的结合位点大小（n）的DNA结合时，UvsX表现出中等水平的协同性（ω =100）。该复合物的盐稳定性研究表明，不可水解的ATP类似物，ATP γ S，诱导高亲和力的结合模式，这是区别于与ADP或在没有核苷酸辅因子的情况下形成的复合物。有了这些新的信息，UvsX和RecA重组酶之间的功能关系，以及UvsX与T4突触前纤维的其他蛋白（UvsY和gp 32）相互作用的影响可能会进一步探讨。(C)北京：科学出版社.
Bacteriophage T4 provides an important model for the biochemistry and genetics of DNA metabolism. Phage-encoded proteins conduct all essential steps of T4 DNA replication, repair, and recombination. Central to these three processes is the T4 UvsX protein, a member of the filamentous, ATP-dependent class of general recombination enzymes typified by the Escherichia coli RecA protein, Like RecA, UvsX forms presynaptic filaments on single-stranded (ss) DNA, which are the obligatory nucleoprotein intermediates in recombination. Aspects of the T4 presynaptic filament are explored by quantitative characterization of the UvsX-ssDNA interaction using an etheno-derivitized single-stranded DNA molecule, epsilon DNA, whose fluorescence is enhanced by UvsX binding. Studies with this model lattice show that UvsX exhibits a moderate level of cooperativity (omega =100) when binding to epsilon DNA with a binding-site size (n) equal to four nucleotide residues. Salt-stability studies of this complex reveal that the non-hydrolyzable ATP analog, ATP gamma S, induces a high-affinity binding mode that is distinguishable from complexes formed with ADP or in the absence of a nucleotide cofactor. With this new information, both functional relationships between the UvsX and RecA recombinases, and implications for UvsX interactions with the other proteins of the T4 presynaptic filament (UvsY and gp32) may be further explored. (C) 1998 Academic Press.