SMC proteins in bacteria: Condensation motors for chromosome segregation?
SMC proteins in bacteria: Condensation motors for chromosome segregation?
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DOI：
10.1016/s0300-9084(00)01218-9
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发表时间：
2001-01-01
期刊：
影响因子：
3.9
通讯作者：
Graumann, PL
中科院分区：
文献类型：
--
作者：
Graumann, PL
SMC 蛋白是一个普遍存在的蛋白家族，除了少数细菌外，几乎存在于迄今为止分析的所有生物体中。它们在真核生物中的染色体凝聚、分离、凝聚和 DNA 重组修复中发挥作用。并能在体外将正扭动引入DNA。 SMC 蛋白和结构同源的 MukB 蛋白是不寻常的 ATP 酶，它们形成反向平行二聚体，具有长卷曲线圈片段，分隔能够结合 DNA 的球状末端。最近，SMC 蛋白已被证明对于细菌染色体浓缩、分离和细胞周期进展至关重要。大肠杆菌拓扑异构酶 I 中 MukB 抑制突变的鉴定表明 SMC 蛋白参与体内负 DNA 超螺旋，并通过这种方式组织和压缩染色体。讨论了一种模型，其中细菌 SMC 蛋白在将复制的染色体起源初步分离到未来的子细胞中后发挥作用，通过在两个细胞半部内浓缩复制的 DNA 链来分离姐妹染色单体。这类似于通过在细胞中两个专门的子区域施加的凝结机制将 DNA 链拉入相对的细胞半部。 (C) 2001 Societr francaise de biochimie et biologie molecularaire / Editions scientifiques et Medicales Elsevier SAS。
SMC proteins are a ubiquitous protein family, present in almost all organisms so far analysed except for a few bacteria. They function in chromosome condensation, segregation, cohesion, and DNA recombination repair in eukaryotes. and can introduce positive writhe into DNA in vitro. SMC proteins and the structurally homologous MukB protein are unusual ATPases that form antiparallel dimers, with long coiled coil segments separating globular ends capable of binding DNA. Recently, SMC proteins have been shown to be essential for chromosome condensation, segregation and cell cycle progression in bacteria. Identification of a suppressor mutation for MukB in topoisomerase I in Escherichia coli suggests that SMC proteins are involved in negative DNA supercoiling in vivo, and by this means organize and compact chromosomes. A model is discussed in which bacterial SMC proteins act after an initial separation of replicated chromosome origins into the future daughter cell, separating sister chromatids by condensing replicated DNA strands within both cell halves. This would be analogous to a pulling of DNA strands into opposite cell halves by a condensation mechanism exerted at two specialised subregions in the cell. (C) 2001 Societr francaise de biochimie et biologie moleculaire / Editions scientifiques et medicales Elsevier SAS.