Undesigned Selection for Replication Termination of Bacterial Chromosomes

JOURNAL OF MOLECULAR BIOLOGY

卷:426

Article

Kono, Nobuaki¹  Arakawa, Kazuharu¹  Sato, Mitsuru¹  Yoshikawa, Hirofumi²  Tomita, Masaru¹  Itaya, Mitsuhiro¹ 

[1] Keio Univ, Inst Adv Biosci, Yamagata 9970017, Japan

[2] Tokyo Univ Agr, Dept Biosci, Tokyo 1568502, Japan

关键词: replication terminus;    circular chromosome;    Bacillus subtilis;    genomic structure;    high-throughput sequencing;   

DOI  :  10.1016/j.jmb.2014.06.005

来源: Elsevier

【 摘 要 】

The oriC DNA replication origin in bacterial chromosomes, the location of which appears to be physically identified, is genetically regulated by relevant molecular machinery. In contrast, the location of the terminus remains obscure for many bacterial replicons, except for terC, the proposed and well-studied chromosome termination site in certain bacteria. The terC locus, which is composed of specific sequences for its binding protein, is located at a site opposite from oriC, exhibiting a symmetric structure around the oriC-terC axis. Here, we investigated Bacillus subtilis 168 strains whose axes were hindered and found that the native terC function was robust. However, eradication of terminus region specific binding protein resulted in the natural terC sites not being used for termination; instead, new termini were selected at a location exactly opposite to oriC. We concluded that replication generally terminates at the loci where the two approaching replisomes meet. This site was automatically selected, and two replisomes moving at the same rate supported symmetrical chromosome structures relative to oriC. The rule, which was even validated by artificial chromosomes irrespective of oriC, should be general for replicons administered by two replisomes. (C) 2014 The Authors. Published by Elsevier Ltd.

【 授权许可】

Free