Fekete Richard A, Chattoraj Dhruba K
Laboratory of Biochemistry, CCR, NCI, NIH, Bldg. 37, Bethesda, MD 20892-4255, USA.
Mol Microbiol. 2005 Jan;55(1):175-83. doi: 10.1111/j.1365-2958.2004.04392.x.
Eukaryotic chromosomes contain a locus, the centromere, at which force is applied to separate replicated chromosomes. A centromere analogue is also found in some bacterial plasmids and chromosomes, although not yet identified in the well-studied Escherichia coli chromosome. We aimed to identify centromere-like sequences in E. coli with the premise that such sequences would be the first to migrate towards the cell poles, away from the cell centre where DNA replication is believed to occur. We have labelled different loci on the chromosome by integrating arrays of binding sites for LacI-EYFP and phage lambdacI-ECFP and supplying these fusion proteins in trans. Comparison of such pairs of loci suggests the presence of a centromere-like site close to the origin of replication. Polar migration of the site was dependent on migS, a locus recently implicated in chromosome migration, thus providing strong support for migS being the E. coli centromere.
真核生物染色体含有一个位点，即着丝粒，在该位点施加力以分离复制后的染色体。在一些细菌质粒和染色体中也发现了着丝粒类似物，尽管在经过充分研究的大肠杆菌染色体中尚未鉴定出。我们旨在鉴定大肠杆菌中类似着丝粒的序列，前提是这些序列将是最先朝着细胞两极迁移的，远离据信发生DNA复制的细胞中心。我们通过整合LacI-EYFP和噬菌体λcI-ECFP的结合位点阵列并反式提供这些融合蛋白，对染色体上的不同位点进行了标记。对这样的位点对进行比较表明，在复制起点附近存在一个类似着丝粒的位点。该位点的极性迁移依赖于migS，migS是最近涉及染色体迁移的一个位点，因此为migS是大肠杆菌着丝粒提供了有力支持。
