Fujita M Q, Yoshikawa H, Ogasawara N
Department of Pathology, Osaka University, Medical School, Japan.
Mol Gen Genet. 1989 Feb;215(3):381-7. doi: 10.1007/BF00427033.
We have cloned from Pseudomonas putida a gene homologous to Escherichia coli dnaA, and determined the sequence of the gene and its neighboring region. The dnaA gene and at least three other genes, dnaN, recF and gyrB, were found to be highly homologous to the genes in the dnaA regions of the E. coli and Bacillus subtilis chromosomes. A non-translatable region of some 600 bp immediately upstream of the dnaA gene is also conserved in the three bacteria and contains 3, 12, and 14 DnaA-boxes (TTATCCACA and closely related sequences) in E. coli, P. putida and B. subtilis, respectively. The present results confirm our hypothesis that the dnaA region is the replication origin region of the ancestral bacterium and that the essential feature of the dnaA and DnaA-box combination is conserved in most eubacteria and plays a central role in initiation of chromosomal replication.
我们从恶臭假单胞菌中克隆出了一个与大肠杆菌dnaA同源的基因，并测定了该基因及其邻近区域的序列。发现dnaA基因以及至少其他三个基因，即dnaN、recF和gyrB，与大肠杆菌和枯草芽孢杆菌染色体dnaA区域中的基因高度同源。在这三种细菌中，dnaA基因上游紧邻的约600 bp不可翻译区域也保守存在，在大肠杆菌、恶臭假单胞菌和枯草芽孢杆菌中分别含有3个、12个和14个DnaA框（TTATCCACA及密切相关序列）。目前的结果证实了我们的假设，即dnaA区域是原始细菌的复制起始区域，并且dnaA和DnaA框组合的基本特征在大多数真细菌中保守存在，并在染色体复制起始中起核心作用。
