关闭凝聚环:它的Smc3-kleisin接口的结构和功能
Thomas G Gligoris1, Johanna C Scheinost1, Frank Bürmann2
1Department of Biochemistry, University of Oxford, Oxford, OX1 3QU, UK.
Science (New York, N.Y.)
|November 22, 2014
概括
凝聚素复合体形成三部分环,以保持姐妹染色体在一起. 这项研究揭示了Smc3/Scc1接口结构,这对凝聚力至关重要.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 凝聚素由Smc1,Smc3和Scc1亚单元组成,对姐妹染色体凝聚力至关重要.
- 合的三环结构被提出来调解这种凝聚力.
- 此前,Smc3/Scc1接口结构及其在凝聚性调节中的作用是未知的.
研究的目的:
- 为了阐明 Smc3/Scc1 接口在凝聚力中的结构和功能意义.
- 研究Smc3/Scc1相互作用如何影响凝聚素与染色体的关联.
- 了解Smc3乙化在调节凝聚素释放中的作用.
主要方法:
- 对Scc1的N端域及其与Smc3.3相互作用的结构分析.
- 局部定向的突变发生来破坏Smc3/Scc1接口.
- 在酵母突变体中评估凝聚素的染色体关联.
- 分析Smc3/Scc1接口和乙化残留物之间的空间关系.
主要成果:
- Scc1的N端域与Smc3腺三酸酶头域形成了一个四螺旋捆,定义了Smc3/Scc1接口.
- 破坏这种接口的突变会损害凝聚蛋白与染色体的关联.
- 描述的Smc3/Scc1接口在空间上与参与乙化依赖释放的Smc3残留物相距甚远.
- 在体内,凝聚素形成异质三元环,捕获姐妹DNA.
结论:
- Smc3/Scc1接口对于保持凝聚素与染色体的稳定关联至关重要.
- 已证实,凝聚素的异质三元环结构可以捕捉姐妹染色体.
- 通过乙化介导的凝聚素释放可能涉及与Smc3/Scc1接口本身不同的调节机制.
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