Global effect of an RNA polymerase β-subunit mutation on gene expression in the radiation-resistant bacterium Deinococcus radiodurans  

作　　者：HUA XiaoTing WANG Hu WANG Chao TIAN Bing HUA YueJin 

机构地区：[1]Department of Infectious Diseases, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou 310016, China [2]Key Laboratory for Nuclear-Agricultural Seiences of the Chinese Ministry of Agriculture and Zhejiang Province, Institute e~f Nuclear-Agricultural Seiences, Zhejiang University, Hangzhou 310029, China

出　　处：《Science China(Life Sciences)》2011年第9期854-862,共9页中国科学（生命科学英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant Nos. 30830006 and 31000045);the National High Technology Research and Development Program of China (Grant No. 2007AA021305);Major Scientific and Technological Project for the Creation of Significant New Drugs (Grant No. 2009ZXJ09001-034);Major Project for Genetically Modified Organism Breeding (Grant No. 2009ZX08009-075B);Application of Nuclear Techniques in Agriculture from Ministry of Agriculture of China (Grant No. 200803034) to Yue-jin Hua;the 2009 Zhejiang Innovation Program for Graduates

摘　　要：The β-subunit of RNA polymerase, which is involved in rifampin binding, is highly conserved among prokaryotes, and Rile mutants detected in many bacteria are the result of amino acid changes. Spontaneous rifampin resistance mutations resulting in amino acid replacement （L420R） and deletion （1258-66 9 bp deletion） have been previously isolated in the rpoB gene of Deinococcus radiodurans. In this study, a β-subunit mutation in D. radiodurans resulted in a unique effect on growth rate. We used DNA microarrays and biochemical assays to investigate how the Rif mutation in the β-subunit led to changes in growth rate via altered regulation of multiple genes. The expression of genes with predicted functions in metabolism, cellular processes and signaling, and information storage and processing were significantly altered in the 9 bp-deletion rpoB mutant. The consensus promoter sequence of up-regulated genes in the 9 bp-deletion rpoB mutant was identified as an AT-rich sequence. Greater levels of reactive oxygen species accumulated in the L420R and 9 bp-deletion rpoB mutants compared with wild type. These results provide insight into the molecular mechanism of how the β-subunit Rif mutation alters the regulation of multiple genes.The β-subunit of RNA polymerase, which is involved in rifampin binding, is highly conserved among prokaryotes, and Rif r mutants detected in many bacteria are the result of amino acid changes. Spontaneous rifampin resistance mutations resulting in amino acid replacement (L420R) and deletion (1258-66 9 bp deletion) have been previously isolated in the rpoB gene of Deinococcus radiodurans. In this study, a β-subunit mutation in D. radiodurans resulted in a unique effect on growth rate. We used DNA microarrays and biochemical assays to investigate how the Rif r mutation in the β-subunit led to changes in growth rate via altered regulation of multiple genes. The expression of genes with predicted functions in metabolism, cellular processes and signaling, and information storage and processing were significantly altered in the 9 bp-deletion rpoB mutant. The consensus promoter sequence of up-regulated genes in the 9 bp-deletion rpoB mutant was identified as an AT-rich sequence. Greater levels of reactive oxygen species accumulated in the L420R and 9 bp-deletion rpoB mutants compared with wild type. These results provide insight into the molecular mechanism of how the β-subunit Rifr mutation alters the regulation of multiple genes.

关 键 词：RPOB RIFAMPIN DEINOCOCCUS transcriptome microarray 

分 类 号：Q756[生物学—分子生物学] TQ460.38[化学工程—制药化工]