枯草芽孢杆菌中线性质粒多聚体的重组依赖性合成的物理和生化特性

Physical and biochemical characterization of recombination-dependent synthesis of linear plasmid multimers in Bacillus subtilis.

作者信息

Leonhardt H, Lurz R, Alonso J C

机构信息

Max-Planck-Institut für Molekulare Genetik, Berlin, FRG.

出版信息

Nucleic Acids Res. 1991 Feb 11;19(3):497-503. doi: 10.1093/nar/19.3.497.

DOI:10.1093/nar/19.3.497

PMID:1901406

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC333639/

Abstract

The synthesis and structure of linear multimeric plasmid molecules (hmw DNA) in Bacillus subtilis were investigated. The replication of covalently-closed-circular supercoiled (form I) DNA requires the rate-limiting plasmid-encoded replication initiation protein. Unlike form I, hmw DNA synthesis is partially resistant to inhibition of cellular transcription or translation and requires the host DnaB protein. In addition, hmw DNA synthesis involves host recombination and repair functions (RecE and Poll). Analysis of hmw DNA by electron microscopy displayed linear DNA molecules up to 100 kb in size, which were either single-stranded, double-stranded or double-stranded with single-stranded ends. Structural features of hmw DNA molecules were mapped by means of heteroduplex studies using defined strand-specific probes. The results suggest that a recombination intermediate, but not plasmid-encoded replication, is involved in the initiation of hmw DNA synthesis.

摘要

对枯草芽孢杆菌中线性多聚体质粒分子（高分子量DNA，hmw DNA）的合成及结构进行了研究。共价闭合环状超螺旋（形式I）DNA的复制需要由质粒编码的限速复制起始蛋白。与形式I不同，hmw DNA的合成对细胞转录或翻译的抑制具有部分抗性，并且需要宿主DnaB蛋白。此外，hmw DNA的合成涉及宿主的重组和修复功能（RecE和Poll）。通过电子显微镜对hmw DNA进行分析，显示出大小达100 kb的线性DNA分子，这些分子要么是单链的，要么是双链的，或者是带有单链末端的双链分子。使用特定的链特异性探针通过异源双链研究绘制了hmw DNA分子的结构特征。结果表明，hmw DNA合成的起始涉及一种重组中间体，而非质粒编码的复制。