枯草芽孢杆菌YvdSR蛋白转运Na^(+)关键残基的研究  

Study on key residues of Na^(+) transport by YvdSR protein transporter from Bacillus subtilis

作　　者：张凌霄 张正来 郑秀桃 姜巨全[1] ZHANG Lingxiao;ZHANG Zhenglai;ZHENG Xiutao;JIANG Juquan(School of Life Sciences,Northeast Agricultural University,Harbin 150030,China)

机构地区：[1]东北农业大学生命科学学院,哈尔滨150030

出　　处：《东北农业大学学报》2024年第5期56-64,共9页Journal of Northeast Agricultural University

基　　金：国家自然科学基金联合基金重点项目(U23A20143);国家自然科学基金面上项目(32070031,31770051)。

摘　　要：对枯草芽孢杆菌(Bacillus subtilis strain 168)双组分基因YvdSR表达的双组分蛋白YvdSR进行功能鉴定,得出YvdSR具有转运Na^(+)/Li^(+)功能,为探究YvdSR离子转运机制,分别对两种组分作同源序列比对,从每种组分中筛选出完全保守的酸性氨基酸残基并进行氨基酸残基定点突变。结果表明,YvdS和YvdR共有的E13在同源物中完全保守且突变为丙氨酸后均失去Na^(+)(Li^(+))/H^(+)逆向转运活性,说明两种组分的E13均是蛋白质行使功能不可或缺的,YvdS的E13A经回复突变后可恢复高水平Na^(+)(Li^(+))/H^(+)逆向转运活性,YvdR的E13A经回复突变后仍失去Na^(+)(Li^(+))/H^(+)逆向转运活性,表明YvdS和YvdR在Na^(+)(Li^(+))/H^(+)逆向转运中行使不同功能。The two-component transporter YvdSR expressed by the two-component gene YvdSR from Bacillus subtilis strain 168 was functionally identified.It was concluded that YvdSR had the func-tion of transporting Na^(+)/Li^(+).In order to explore the ion transport mechanism of YvdSR,the homologous sequence alignment of the two components was carried out,and completely conserved acidic amino acid residues were screened from each component and site-directed mutagenesis of amino acid residues was carried out.The E13 shared by YvdS and YvdR was completely conserved in the homologues and lost Na^(+)(Li^(+))/H^(+)reverse transport activity after mutation to alanine,indicating that the E13 of both components was indispensable for protein function.In addition,the E13A of YvdS could restore high levels of Na^(+)(Li^(+))/H^(+)reverse transport activity after reverse mutation,while the E13A of YvdR still lost Na^(+)(Li^(+))/H^(+)reverse transport activity after reverse mutation,indicating that YvdS and YvdR had different functions in Na^(+)(Li^(+))/H^(+)reverse transport.

关 键 词：Na^(+)/H^(+)逆向转运 YvdSR 膜蛋白 定点突变 

分 类 号：Q933[生物学—微生物学] Q751