Mellado E, Asturias J A, Nieto J J, Timmis K N, Ventosa A
Department of Microbiology and Parasitology, Faculty of Pharmacy, University of Seville, Spain.
J Bacteriol. 1995 Jun;177(12):3443-50. doi: 10.1128/jb.177.12.3443-3450.1995.
The moderately halophilic bacterium Chromohalobacter marismortui contains a 17.5-kb narrow-host-range plasmid, pCM1, which shows interesting properties for the development of cloning vectors for the genetic manipulation of this important group of extremophiles. Plasmid pCM1 can stably replicate and is maintained in most gram-negative moderate halophiles tested. The replication origin has been identified and sequenced, and the minimal pCM1 replicon has been localized to a 1,600-bp region which includes two functionally discrete regions, the oriV region and the repA gene. oriV, located on a 700-bp fragment, contains four iterons 20 bp in length adjacent to a DnaA box that is dispensable but required for efficient replication of pCM1, and it requires trans-acting functions. The repA gene, which encodes a replication protein of 289 residues, is similar to the replication proteins of other gram-negative bacteria.
中度嗜盐细菌死海嗜盐色杆菌含有一个17.5kb的窄宿主范围质粒pCM1，该质粒对于开发用于对这一重要嗜极端微生物群体进行基因操作的克隆载体具有有趣的特性。质粒pCM1能够稳定复制，并在所测试的大多数革兰氏阴性中度嗜盐菌中得以维持。复制起点已被鉴定和测序，最小的pCM1复制子已定位到一个1600bp的区域，该区域包括两个功能上不同的区域，即oriV区域和repA基因。oriV位于一个700bp的片段上，包含四个长度为20bp的迭代子，与一个DnaA框相邻，该DnaA框对于pCM1的有效复制是可有可无但必需的，并且它需要反式作用功能。repA基因编码一个由289个残基组成的复制蛋白，与其他革兰氏阴性细菌的复制蛋白相似。
