南极嗜冷假单胞菌7197 S- 腺苷同型半胱氨酸水解酶 ( SAHH) 基因的克隆与序列分析

从南极普利兹湾深海沉积物中筛选到一株耐冷菌株7197，其16S rDNA序列分析表明该菌株属于假单胞菌属（Pseudomonas）。作者通过设计引物，从该菌的全基因组DNA中克隆到编码S-腺苷-L-高半胱氨酸（SAHH）的完整ORF，全长为1424bp。使用DNAMAN（5，1）软件对全长ORF为1424bp的SAHH基因进行分析，SAHH基因编码一个由474AA残基组成、分子量预计为52523Da的SAHH蛋白质，与Psychrobacter sp．273—4的SAHH有96．84％的相似性；与Acinetobacter sp．ADP1的SAHH有79％的相似性；与Pseudomonas fluorescens Pf-5的SAHH有75％的相似性。

Analysis and Gene Cloning of the S- adenosylhomocysteine Hydrolase from Antarctic Psychrotrophilic Pseudomonas sp. 7197 Strain

A strain 7197, which produces S - adenosyl - L - homocysteine hydrolase, was isolated from the deep sea sediment of Prydz Bay, Antarctic. The morphology identification and 16S rDNA sequence analysis showed that it belonged to genus Pseudomonas, The S- adenosylhomocysteine hydrolase gene was cloned by PCR according to the primers. Nucleotide sequence analysis revealed an open reading frame of 1424 bp encoding the SAHH, The amino acid sequence deduced from the nucleotide sequence of the SAHH gene corresponded to a protein of 474 amino acid residues with a molecular weight of 52,523 kDa, The SAHH shows a high sequence similarity to the SAHH gene from Psychrobacter sp, 273 - 4 and Acinetobacter sp. ADP1, with homologies of 96.84% and 79%, respectively, also show some sequence similarity to the SAHH gene from Pseudomonas fluorescens Pf- 5 with 75 % homologies.