Huang Junyan, Han Dongmei, Yu Ziniu, Sun Ming
State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, Hubei, 430070, People's Republic of China.
Arch Microbiol. 2007 Jul;188(1):47-53. doi: 10.1007/s00203-007-0222-0. Epub 2007 Feb 20.
A new cryptic plasmid pBMB175 from Bacillus thuringiensis subsp. tenebrionis YBT-1765 was isolated and characterized. Sequence analysis showed that pBMB175 (14,841 bp and 31% GC content) contained at least eighteen putative open reading frames (ORFs), among which nine ORFs displayed the homology with the hypothetical proteins in rolling-circle replication plasmid pGI3. Deletion analysis revealed that the pBMB175 minireplicon located in a novel 1,151 bp fragment. This fragment contains ORF7 coding sequence, which encodes a protein (Rep175, 149 amino acids [aa]) indispensable for plasmid replication. Rep175 has no significant homology with known function proteins. Furthermore, a putative double-strand origin (dso), having no DNA similarity with characterized dso of other replicon so far, was identified in this minireplicon fragment. These features showed that pBMB175 could be placed into a new plasmid family.
从苏云金芽孢杆菌亚种黄粉虫变种YBT - 1765中分离并鉴定出一种新的隐蔽质粒pBMB175。序列分析表明，pBMB175（14,841 bp，GC含量为31%）至少包含18个推定的开放阅读框（ORF），其中9个ORF与滚环复制质粒pGI3中的假定蛋白具有同源性。缺失分析表明，pBMB175的最小复制子位于一个新的1,151 bp片段中。该片段包含ORF7编码序列，其编码一种对质粒复制必不可少的蛋白质（Rep175，149个氨基酸[aa]）。Rep175与已知功能的蛋白质没有显著同源性。此外，在该最小复制子片段中鉴定出一个推定的双链起源（dso），到目前为止，它与其他复制子已鉴定的dso没有DNA相似性。这些特征表明pBMB175可归入一个新的质粒家族。
