MukEF Is required for stable association of MukB with the chromosome.
MukEF Is required for stable association of MukB with the chromosome.
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MukEF 是 MukB 与染色体稳定关联所必需的。
DOI：
10.1128/jb.00770-07
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发表时间：
2007
影响因子：
3.2
通讯作者：
Rybenkov,ValentinV
中科院分区：
文献类型：
--
作者：
She,Weifeng;Wang,Qinhong;Mordukhova,ElenaA;Rybenkov,ValentinV
MukB是大肠杆菌染色体正确折叠所必需的SMC蛋白。MukB与两种非SMC蛋白MukE和MukF复合作用。MukEF的作用尚不清楚。MukEF在体外破坏MukB-DNA相互作用。然而，在体内，MukEF刺激MukB诱导的DNA缩合，并且是在细胞长度的四分之一位置处组装MukB簇所必需的。我们在这里报告，MukEF是必不可少的MukB与染色体的稳定协会。我们发现MukBEF与染色体形成稳定的复合物，该复合物在温和的细胞裂解后与类核共纯化。在MukEF不存在或过量产生时，可以在类核中发现小MukB。类似地，过量产生的MukEF从其四分之一位置募集MukB-绿色荧光蛋白（GFP），表明MukB-GFP簇的形成和与染色体的稳定缔合可能是机械相关的。最后，我们报告MukE-GFP在细胞长度的四分之一位置形成焦点，但在缺乏MukB或过度产生MukEF的细胞中不形成焦点，这表明簇是由MukBEF形成的，而不是由其单个亚基形成的。这些数据支持这样的观点，即MukBEF在染色体组织中充当大分子组装、支架，并且MukEF对于该支架的组装是必不可少的。
MukB is a bacterial SMC(structural maintenance of chromosome) protein required for correct folding of theEscherichia colichromosome. MukB acts in complex with the two non-SMC proteins, MukE and MukF. The role of MukEF is unclear. MukEF disrupts MukB-DNA interactions in vitro. In vivo, however, MukEF stimulates MukB-induced DNA condensation and is required for the assembly of MukB clusters at the quarter positions of the cell length. We report here that MukEF is essential for stable association of MukB with the chromosome. We found that MukBEF forms a stable complex with the chromosome that copurifies with nucleoids following gentle cell lysis. Little MukB could be found with the nucleoids in the absence or upon overproduction of MukEF. Similarly, overproduced MukEF recruited MukB-green fluorescent protein (GFP) from its quarter positions, indicating that formation of MukB-GFP clusters and stable association with the chromosome could be mechanistically related. Finally, we report that MukE-GFP forms foci at the quarter positions of the cell length but not in cells that lack MukB or overproduce MukEF, suggesting that the clusters are formed by MukBEF and not by its individual subunits. These data support the view that MukBEF acts as a macromolecular assembly, a scaffold, in chromosome organization and that MukEF is essential for the assembly of this scaffold.