短短芽孢杆菌TetR基因家族的鉴定及表达模式分析

Identification and expression analysis of TetR gene family of Brevibacillus brevis

采用生物信息学方法从生防菌短短芽孢杆菌(Brevibacillus brevis)X23全基因组水平鉴定出13个TetR家族基因,将其命名为BbTetR1、…、BbTetR13,对其基本性质、基因结构和高级结构进行分析。结果表明:短短芽孢杆菌TetR家族成员在进化上具有保守性,基因序列长度为477~681 bp,编码的蛋白由168~226个氨基酸组成,相对分子质量为1.9×10^(4)~2.57×10^(4),等电点为4.84~7.77;其基因家族成员可划分为3个亚族,亚族Ⅰ包含5个成员,亚族Ⅱ、亚族Ⅲ各包含4个成员;所有BbTetR蛋白均含有大量α-螺旋,且这些蛋白的空间结构呈现多样化;转录组分析结果表明,不同的BbTetR在短短芽孢杆菌不同生长时期的表达模式和表达量差异显著,BbTetR1、BbTetR5、BbTetR8和BbTetR10在短短芽孢杆菌不同生长阶段均有较高表达,推测其可能发挥更重要的调控作用。

In this study,13 TetR genes(BbTetR1,…,BbTetR13)at whole genome level of biocontrol bacteria Brevibacillus brevis X23 were identified using bioinformatics methods for the first time.The results of basic property,gene structure and high-level structural analysis showed that the members of TetR gene family were conservative in evolution.The length of the gene sequences ranged from 477 to 681 bp,with 168 and 226 amino acids respectively.The molecular weights of the family proteins ranged from 1.9×10^(4) to 2.57×10^(4) and the isoelectric points were 4.84 to 7.77.According to the phylogenetic tree,TetR genes could be divided into three clades.Group I contained 5 members,group II 4 members,and groupⅢ4 members;All Bb TetR proteins contained a large number ofα-helixes and their spatial structures were diverse.The results of transcriptome analysis showed that the expression patterns and levels of different BbTetRs in different growth stages were significantly different.BbTetR1,BbTetR5,BbTetR8 and BbTetR10 had higher expression in different growth stages of Bacillus brevis,suggesting that they may play an important role in protein expression regulation.