光合菌Rhodobacter sphaeroides 601hupT基因的克隆与功能分析

从紫色非硫光合细菌Rhodobacter sphaeroides 601的吸氢酶(hup)基因簇中,克隆了hupT基因,并对该基因进行了测序,分析了由其推测的氨基酸序列的同源性.hupT基因全长1 332 bp,编码一分子量约为48 23 kD的蛋白.将hupT基因引入大肠杆菌进行了体外表达.纯化基因产物HupT,并进行HupT的自身磷酸化分析.结果表明,HupT属于双组份调节系统中的组氧酸蛋白激酶.将hupT基因导入光合菌Rhodobacter capsulatus吸氢酶负调节基因突变株BSE8后.野生型吸氢酶的表型得以恢复,说明所克隆的R.sphaeroides 601中的hupT基因在吸氢酶的表达中起负调节作用.

Sequence and Function Analysis of hupT Gene in Rhodobacter sphaeroides 601

The hupT gene from hup cluster(cosmid I) in Rhodobacter sphaeroides was cloned and sequenced. It has been found to have a length of 1 332 bp and to encode a 48.23 kD protein homologous to histidine kinase belonging to the superfamily of two component regulatory system(Figs.1,2). The HupT was overexpressed in E.coli and purified(Fig.3). The auto phosphorylation of HupT showed that it was a histidine kinase(Fig.4). And the hupT gene could restore hydrogenase activity in R.capsulatus HupT mutant(Table 2).