Wu Wei, Leblanc Shannon K D, Piktel James, Jensen Susan E, Roy Kenneth L
Department of Biological Sciences, CW 405 Biological Sciences Bldg., University of Alberta, Edmonton, Canada.
Can J Microbiol. 2006 Apr;52(4):293-300. doi: 10.1139/w05-126.
pSCL2 (120 kb), one of the linear plasmids found in Streptomyces clavuligerus NRRL3585, was isolated and partially sequenced. Computational analysis of the central region of pSCL2 revealed the presence of two open reading frames that appear to encode proteins highly homologous to RepL1 and RepL2, replication proteins from pSLA2-L, the large linear plasmid in Streptomyces rochei. The S. clavuligerus open reading frames were designated repC1 and repC2, encoding the proteins RepC1 (150 amino acids) and RepC2 (102 amino acids), respectively. The RepC and RepL proteins have identical translation features and very similar predicted secondary and tertiary structures. Functional analysis confirmed that RepC1 is essential for replication initiation of pSCL2, whereas RepC2 is dispensable but may play a role in copy number control. The RepC and RepL proteins do not show similarity to any other bacterial plasmid replication proteins. Three regions of DNA sequence, Box 1 (1050-850 bp), Box 2 (723-606 bp), and Box 3 (224-168 bp), located upstream of repC1, were also shown to be essential or very important for replication of pSCL2.
pSCL2（120 kb）是在棒状链霉菌NRRL3585中发现的线性质粒之一，已被分离并进行了部分测序。对pSCL2中心区域的计算分析表明，存在两个开放阅读框，它们似乎编码与RepL1和RepL2高度同源的蛋白质，RepL1和RepL2是来自罗氏链霉菌中大线性质粒pSLA2-L的复制蛋白。棒状链霉菌的开放阅读框被命名为repC1和repC2，分别编码蛋白质RepC1（150个氨基酸）和RepC2（102个氨基酸）。RepC和RepL蛋白具有相同的翻译特征以及非常相似的预测二级和三级结构。功能分析证实，RepC1对于pSCL2的复制起始至关重要，而RepC2是可有可无的，但可能在拷贝数控制中发挥作用。RepC和RepL蛋白与任何其他细菌质粒复制蛋白均无相似性。位于repC1上游的三个DNA序列区域，即Box 1（1050 - 850 bp）、Box 2（723 - 606 bp）和Box 3（224 - 168 bp），也被证明对pSCL2的复制至关重要或非常重要。
