Dimerization and DNA-dependent aggregation of the Escherichia coli nucleoid protein and chaperone CbpA.
Dimerization and DNA-dependent aggregation of the Escherichia coli nucleoid protein and chaperone CbpA.
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DOI：
10.1111/j.1365-2958.2010.07292.x
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发表时间：
2010-09
影响因子：
3.6
通讯作者：
Grainger DC
中科院分区：
文献类型：
--
作者：
Cosgriff S;Chintakayala K;Chim YT;Chen X;Allen S;Lovering AL;Grainger DC
大肠杆菌弯曲DNA结合蛋白A（CbpA）是一种核苷酸相关的DNA结合因子和伴侣蛋白，在细胞进入稳定期时以高水平表达。使用遗传学，生物化学，结构建模和单分子原子力显微镜的组合，我们已经研究了二聚化，和DNA结合，CbpA。我们的数据表明，GbpA二聚化是由疏水性表面驱动的，该表面包含位于靠近GbpA C末端的α螺旋同一侧的氨基酸侧链W287和L290。不能二聚化的CbpA衍生物也不能结合DNA。游离于溶液中，CbpA可以单体或二聚体形式存在。然而，当与DNA结合时，CbpA形成大的聚集体，可以保护DNA免受核酸酶的降解。这些CbpA-DNA聚集体在形态上类似于由来自饥饿细胞（Dps）的DNA结合蛋白形成的蛋白-DNA复合物，Dps是唯一的其他固定相特异性类核蛋白。相反，由主要生长期类核蛋白Fis形成的蛋白-DNA复合物具有明显不同的外观。
The Escherichia coli curved DNA-binding protein A (CbpA) is a nucleoid-associated DNA-binding factor and chaperone that is expressed at high levels as cells enter stationary phase. Using a combination of genetics, biochemistry, structural modelling and single-molecule atomic force microscopy we have examined dimerization of, and DNA binding by, CbpA. Our data show that CbpA dimerization is driven by a hydrophobic surface comprising amino acid side chains W287 and L290 located on the same side of an α helix close to the C-terminus of CbpA. Derivatives of CbpA that are unable to dimerize are also unable to bind DNA. Free in solution, CbpA can exist as either a monomer or dimer. However, when bound to DNA, CbpA forms large aggregates that can protect DNA from degradation by nucleases. These CbpA–DNA aggregates are similar in morphology to protein–DNA complexes formed by the DNA-binding protein from starved cells (Dps), the only other stationary phase-specific nucleoid protein. Conversely, protein–DNA complexes formed by Fis, the major growth phase nucleoid protein, have a markedly different appearance.
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影响因子：
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