Hatt C, Ward M E, Clarke I N
Department of Microbiology, Faculty of Medicine (University of Southampton), Southampton General Hospital, UK.
Nucleic Acids Res. 1988 May 11;16(9):4053-67. doi: 10.1093/nar/16.9.4053.
Chlamydia trachomatis serovar L1/440/LN possesses a 7498bp plasmid which was designated pLGV440. The plasmid was cloned at the BamH1 site of pAT153 into Escherichia coli and the recombinant plasmid was designated pCTL1. A detailed restriction endonuclease map of pCTL1 was constructed. A fragment of the chlamydial plasmid was shown to function as a promoter in E. coli when placed upstream of the lacZ gene. The entire plasmid was sequenced by the chain termination method. Open reading frames were identified from the resulting consensus sequence together with a candidate for the plasmid origin of replication consisting of four perfect tandem repeats of a 22bp sequence, an A:T rich sequence and an open reading frame which could generate a 34.8kdal product. The predicted polypeptide products of the open reading frames were compared by computer with all reported protein sequences. Homology of the predicted polypeptide product of an open reading frame to the E. coli dnaB protein and the analogous product of gene 12 of bacteriophage P22 is described.
沙眼衣原体L1/440/LN血清型含有一个7498bp的质粒，命名为pLGV440。该质粒在pAT153的BamH1位点被克隆到大肠杆菌中，重组质粒命名为pCTL1。构建了pCTL1详细的限制性内切酶图谱。当衣原体质粒片段置于lacZ基因上游时，显示其在大肠杆菌中起启动子作用。采用链终止法对整个质粒进行了测序。从所得的共有序列中鉴定出开放阅读框，以及由一个22bp序列的四个完美串联重复、一个富含A:T的序列和一个可产生34.8kdal产物的开放阅读框组成的质粒复制起点候选序列。通过计算机将开放阅读框预测的多肽产物与所有已报道的蛋白质序列进行比较。描述了一个开放阅读框预测的多肽产物与大肠杆菌dnaB蛋白以及噬菌体P22基因12的类似产物的同源性。
