解淀粉芽孢杆菌BamHI甲基转移酶基因克隆、功能鉴定与序列分析

Cloning,Expression and Nucleotide Sequence Analysis of Gene Encoding for BamHI Methyltransferase from Baillus amyloliquefaciens CICIM B2125

从解淀粉芽孢杆菌Baillus amyloliquefaciens CICIM B2125中克隆了BamHI甲基转移酶基因(bamHIM),并在大肠杆菌JM109中得到了成功表达。该基因含有1271bp的开放阅读框(ORF),编码423个氨基酸,成熟蛋白分子量为49kD。该基因在自身启动子引导下,表达了具有活性的BamHI甲基转移酶(M.BamHI)。该酶可以将BamHI位点的碱基甲基化。氨基酸序列分析表明该酶存在有NADB_Rossmann结构域。

A gene encoding for BamHI methyltransferase（bamHIM） was cloned from Baillus amyloliquefaciens CICIM B2125. The bamHIM was expressed under its own promoter in E. coli JM109. The gene contained an opening reading frame（ORF） of 1 271 bp, which coded for 423 amino acid residues. The molecular weight of mature protein was 49 kD. The BamHI site could be methylased by the enzyme M. BamHI. The amino acid sequence analysis revealed that the enzyme contained a domain of Rossmann-fold NAD （ P ） （ ＋ ）-binding proteins.