乳酸乳球菌乳亚种M14中一个小隐秘质粒的DNA序列分析

DNA sequence analysis of a small cryptic plasmid from Lactococcus lactis subsp. lactis M14.

作者信息

Raha A R, Hooi W Y, Mariana N S, Radu S, Varma N R S, Yusoff K

机构信息

Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.

出版信息

Plasmid. 2006 Jul;56(1):53-61. doi: 10.1016/j.plasmid.2006.03.003. Epub 2006 May 3.

DOI:10.1016/j.plasmid.2006.03.003

PMID:16675013

Abstract

A small plasmid designated pAR141 was isolated from Lactococcus lactis subsp. lactis M14 and its complete 1,594 base pair nucleotide sequence was determined. Analysis of the sequence indicated that this plasmid does not carry any industrially important determinants besides the elements involved in plasmid replication and control. The transcriptional repressor CopG and replication initiation protein RepB appeared as a single operon. A small countertranscribed RNA (ctRNA) coding region was found between the copG and repB genes. The double strand origin (dso) and single strand origin (sso) of rolling circle replicating (RCR) plasmids were also identified in pAR141, suggesting that this plasmid replicates by rolling circle (RC) mode. This observation was supported by S1 nuclease and Southern hybridization analyses.

摘要

从乳酸乳球菌乳酸亚种M14中分离出一个名为pAR141的小质粒，并测定了其完整的1594个碱基对的核苷酸序列。序列分析表明，该质粒除了携带参与质粒复制和控制的元件外，不携带任何具有重要工业价值的决定因素。转录阻遏物CopG和复制起始蛋白RepB表现为一个单一的操纵子。在copG和repB基因之间发现了一个小的反向转录RNA（ctRNA）编码区。在pAR141中还鉴定出了滚环复制（RCR）质粒的双链起始点（dso）和单链起始点（sso），这表明该质粒通过滚环（RC）模式进行复制。S1核酸酶和Southern杂交分析支持了这一观察结果。