一个新的Br蛋白基因部分序列测定及分析

从新疆北部艾比湖分离纯化到极端嗜盐古生菌AB1,采用PCR方法扩增了其16S rRNA基因（16S rDNA）和编码螺旋C至螺旋G的细菌视紫红质（bacteriorhodopsin,Br）蛋白基因片段,并测定了基因的核苷酸序列。基于16S rDNA序列的同源性比较及系统发育学研究表明,AB1是Natronococcus属中新成员。通过对菌株AB1的Br蛋白亲水性分析表明,AB1的Br蛋白与已报道Br蛋白有类似的超二级结构,进一步的蛋白质序列聚合比对结果表明,AB1中Br蛋白螺旋C至螺旋G的氨基酸序列与其他菌株差异明显。研究结果表明菌株AB1的Br蛋白是一种新的Br蛋白。Abstract: A strain of halophilic archaeum AB1 was isolated and purified from Aibi Lake located in the north of Xinjiang Uygur Autonomous Region. Partial DNA fragment encoding a bateriorhodopsin (Br) protein as well as 16S rRNA of AB1 was amplified by PCR, and their nucleotide sequences were determined subsequently. On the basis of homology and phylognetic analysis about 16S rRNA gene (16S rDNA), it could be speculated that the strain AB1 is a novel member of the genus Natronococcus. The hydrophathy analysis of Br fragment revealed that the AB1 Br had a transmembrane heptahelical structure similar to that of other Brs. On the other hand, homology alignment using the deduced partial amino acid sequence of Br protein of AB1 with other Br proteins showed that AB1 Br protein is obviously different to others. These facts indicated that the Br in halophilic archaeum AB1 is a new Br protein.