Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, MD 20850, USA.
Archaea. 2010 Dec 1;2010:505693. doi: 10.1155/2010/505693.
The minichromosome maintenance (MCM) complex is thought to function as the replicative helicase in archaea, separating the two strands of chromosomal DNA during replication. The catalytic activity resides within the C-terminal region of the MCM protein, while the N-terminal portion plays an important role in DNA binding and protein multimerization. An alignment of MCM homologues from several archaeal species revealed a number of conserved amino acids. Here several of the conserved residues located on the surface of the helicase have been mutated and their roles in MCM functions determined. It was found that some mutations result in increased affinity for ssDNA while the affinity for dsDNA is decreased. Other mutants exhibit the opposite effect. Thus, the data suggest that these conserved surface residues may participate in MCM-DNA interactions.
微染色体维持（MCM）复合物被认为在古菌中作为复制解旋酶发挥作用，在复制过程中分离染色体 DNA 的两条链。催化活性位于 MCM 蛋白的 C 末端区域，而 N 末端部分在 DNA 结合和蛋白质多聚化中起着重要作用。对来自几种古菌的 MCM 同源物的比对揭示了许多保守的氨基酸。在这里，对位于解旋酶表面的几个保守残基进行了突变，并确定了它们在 MCM 功能中的作用。结果发现，一些突变导致对 ssDNA 的亲和力增加，而对 dsDNA 的亲和力降低。其他突变体则表现出相反的效果。因此，数据表明这些保守的表面残基可能参与 MCM-DNA 相互作用。
