Identification of a unique domain essential for Escherichia coli DNA topoisomerase III-catalysed decatenation of replication intermediates
Identification of a unique domain essential for Escherichia coli DNA topoisomerase III-catalysed decatenation of replication intermediates
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DOI：
10.1046/j.1365-2958.2000.01763.x
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发表时间：
2000-02-01
影响因子：
3.6
通讯作者：
DiGate, RJ
中科院分区：
文献类型：
--
作者：
Li, ZY;Mondragón, A;DiGate, RJ
已在大肠杆菌 DNA 拓扑异构酶 III (Topo III) 中鉴定出一个 17 个氨基酸残基结构域，该结构域对于 Topo III 介导的 DNA 复制中间体体外解析至关重要。删除该结构域使 Topo III 催化的 DNA 复制中间体的分辨率和多连接质粒 DNA 二聚体的串联降低了四个数量级，而 Topo III 催化的负超螺旋 DNA 底物的松弛仅降低了 20 倍。已在多种质粒编码的拓扑异构酶中检测到该结构域的存在，这提高了这些酶也可能是十链酶的可能性。
A 17-amino-acid residue domain has been identified in Escherichia coli DNA topoisomerase III (Topo III) that is essential for Topo III-mediated resolution of DNA replication intermediates in vitro. Deletion of this domain reduced Topo III-catalysed resolution of DNA replication intermediates and decatenation of multiply linked plasmid DNA dimers by four orders of magnitude, whereas reducing Topo III-catalysed relaxation of negatively supercoiled DNA substrates only 20-fold. The presence of this domain has been detected in multiple plasmid-encoded topoisomerases, raising the possibility that these enzymes may also be decatenases.