DNA Helicases.
DNA Helicases.
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DOI：
10.1128/ecosalplus.4.4.8
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发表时间：
2010-09
期刊：
影响因子：
--
通讯作者：
Bianco PR
中科院分区：
文献类型：
--
作者：
Bianco PR
DNA和RNA解旋酶根据序列比对、生化数据和可用的晶体结构被组织成六个超家族。DNA解旋酶在每个超家族中都有发现，它是一组基本的马达蛋白，在与核苷5‘-三磷酸的水解相耦合的过程中，将DNA双链解离成其组成的单链。DNA解离的目的是为DNA修复、复制和重组过程提供新生的单链DNA(SsDNA)。不足为奇的是，DNA解旋酶具有共同的生化特性，包括与单链和双链DNA的结合，核苷5‘-三磷酸的结合和水解，以及核苷5’-三磷酸的水解偶联，双链DNA的极性解离。这些酶参与DNA新陈代谢的方方面面，因为需要将双链基因组的小区域瞬时分离成其组成链，以便发生复制、重组和修复。在大肠杆菌中，目前有12种DNA解旋酶执行各种任务，从复制叉处的简单链分离到DNA修复和基因重组中的更复杂过程。在本章中，讨论了十二种解旋酶的超家族分类、在DNA代谢中的作用、突变的影响、生化分析、寡聚性以及相互作用的伙伴蛋白。
DNA and RNA helicases are organized into six superfamilies of enzymes on the basis of sequence alignments, biochemical data, and available crystal structures. DNA helicases, members of which are found in each of the superfamilies, are an essential group of motor proteins that unwind DNA duplexes into their component single strands in a process that is coupled to the hydrolysis of nucleoside 5′-triphosphates. The purpose of this DNA unwinding is to provide nascent, single-stranded DNA (ssDNA) for the processes of DNA repair, replication, and recombination. Not surprisingly, DNA helicases share common biochemical properties that include the binding of single- and double-stranded DNA, nucleoside 5′-triphosphate binding and hydrolysis, and nucleoside 5′-triphosphate hydrolysis-coupled, polar unwinding of duplex DNA. These enzymes participate in every aspect of DNA metabolism due to the requirement for transient separation of small regions of the duplex genome into its component strands so that replication, recombination, and repair can occur. In Escherichia coli, there are currently twelve DNA helicases that perform a variety of tasks ranging from simple strand separation at the replication fork to more sophisticated processes in DNA repair and genetic recombination. In this chapter, the superfamily classification, role(s) in DNA metabolism, effects of mutations, biochemical analysis, oligomeric nature, and interacting partner proteins of each of the twelve DNA helicases are discussed.