古菌 MCM 起始端结构域的 1.8 Å 晶体结构呈现右手螺旋丝状。
The 1.8-Å crystal structure of the N-terminal domain of an archaeal MCM as a right-handed filament.
机构信息
Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
Molecular and Computational Biology Program, Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA; Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA; Center of Excellence in NanoBiophysics, University of Southern California, Los Angeles, CA 90089, USA; Norris Comprehensive Cancer Center, University of Southern California, Los Angeles, CA 90089, USA.
出版信息
J Mol Biol. 2014 Apr 3;426(7):1512-23. doi: 10.1016/j.jmb.2013.12.025. Epub 2013 Dec 27.
Mini-chromosome maintenance (MCM) proteins are the replicative helicase necessary for DNA replication in both eukarya and archaea. Most of archaea only have one MCM gene. Here, we report a 1.8-Å crystal structure of the N-terminal MCM from the archaeon Thermoplasma acidophilum (tapMCM). In the structure, the MCM N-terminus forms a right-handed filament that contains six subunits in each turn, with a diameter of 25Å of the central channel opening. The inner surface is highly positively charged, indicating DNA binding. This filament structure with six subunits per turn may also suggests a potential role for an open-ring structure for hexameric MCM and dynamic conformational changes in initiation and elongation stages of DNA replication.
微染色体维持（MCM）蛋白是真核生物和古菌中进行 DNA 复制所必需的复制解旋酶。大多数古菌只有一个 MCM 基因。在这里，我们报告了来自嗜酸性热原体（Thermoplasma acidophilum）的 N 端 MCM 的 1.8Å 晶体结构（tapMCM）。在该结构中，MCM N 端形成右手螺旋丝，每一转包含六个亚基，中央通道开口的直径为 25Å。内表面带高度正电荷，表明其具有 DNA 结合能力。这种每转六个亚基的螺旋丝结构可能表明六聚体 MCM 的开环结构及其在 DNA 复制起始和延伸阶段的动态构象变化具有潜在作用。
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