Yoshida K, Sano H, Seki S, Oda M, Fujimura M, Fujita Y
Department of Biotechnology, Faculty of Engineering, Fukuyama University, Japan.
Microbiology (Reading). 1995 Feb;141 ( Pt 2):337-43. doi: 10.1099/13500872-141-2-337.
Within the framework of an international project for the sequencing of the entire Bacillus subtilis genome, a 29 kb chromosome segment, which contains the hut operon (335 degrees) and the wapA gene, has been cloned and sequenced. This region (28,954 bp) contains 21 complete ORFs and one partial one. The 5th, 6th and 17th genes correspond to hutH encoding histidase, hutP encoding the positive regulator for the hut operon and wapA encoding a precursor of three major wall-associated proteins, respectively. A homology search for their products deduced from the 21 complete ORFs revealed that nine of them exhibit significant homology to known proteins such as urocanase (Pseudomonas putida), a protein involved in clavulanic acid biosynthesis (Streptomyces griseus), amino acid permeases (lysine, Escherichia coli; histidine, Saccharomyces cerevisiae; and others), beta-glucoside-specific phosphotransferases (E. coli and Erwinia chrysanthemi) and 6-phospho-beta-glucosidases (E. coli and Erw. chrysanthemi). Based on the features of the determined sequence and the results of the homology search, as well as on genetic data and sequence of the hut genes reported by other groups, it is predicted that the B. subtilis hut operon may consist of the following six genes (6th-1st), the last of which is followed by a typical rho-independent transcription terminator: hutP, hutH, EE57A (hutU) encoding urocanase, EE57B (hutI) encoding imidazolone-5-propionate hydrolase, EE57C (hutG) encoding formiminoglutamate hydrolase and EE57D (tentatively designated as hutM) possibly encoding histidine permease. Interestingly, the direction of transcription of these hut genes is opposite to that of the movement of the replication fork.
在一项对枯草芽孢杆菌全基因组进行测序的国际项目框架内,一个包含hut操纵子(335°)和wapA基因的29 kb染色体片段已被克隆并测序。该区域(28,954 bp)包含21个完整的开放阅读框(ORF)和1个部分开放阅读框。第5、6和17个基因分别对应编码组氨酸酶的hutH、编码hut操纵子正调控因子的hutP以及编码三种主要壁相关蛋白前体的wapA。对从21个完整ORF推导的产物进行同源性搜索发现,其中9个与已知蛋白具有显著同源性,如尿刊酸酶(恶臭假单胞菌)、参与棒酸生物合成的蛋白(灰色链霉菌)、氨基酸通透酶(赖氨酸,大肠杆菌;组氨酸,酿酒酵母等)、β-葡萄糖苷特异性磷酸转移酶(大肠杆菌和菊欧文氏菌)以及6-磷酸-β-葡萄糖苷酶(大肠杆菌和菊欧文氏菌)。基于所确定序列的特征、同源性搜索结果,以及其他研究小组报道的hut基因的遗传数据和序列,预测枯草芽孢杆菌hut操纵子可能由以下六个基因(第6个-第1个)组成,其中最后一个基因之后是一个典型的不依赖ρ因子的转录终止子:hutP、hutH、编码尿刊酸酶的EE57A(hutU)、编码咪唑啉酮-5-丙酸水解酶的EE57B(hutI)、编码亚胺甲基谷氨酸水解酶的EE57C(hutG)以及可能编码组氨酸通透酶的EE57D(暂定为hutM)。有趣的是,这些hut基因的转录方向与复制叉移动方向相反。