RRC ID 33536
著者 Yamamoto H, Serizawa M, Thompson J, Sekiguchi J.
タイトル Regulation of the glv operon in Bacillus subtilis: YfiA (GlvR) is a positive regulator of the operon that is repressed through CcpA and cre.
ジャーナル J Bacteriol
Abstract Maltose metabolism and the regulation of the glv operon of Bacillus subtilis, comprising three genes, glvA (6-phospho-alpha-glucosidase), yfiA (now designated glvR), and glvC (EIICB transport protein), were investigated. Maltose dissimilation was dependent primarily upon the glv operon, and insertional inactivation of either glvA, glvR, or glvC markedly inhibited growth on the disaccharide. A second system (MalL) contributed to a minor extent to maltose metabolism. Northern blotting revealed two transcripts corresponding to a monocistronic mRNA of glvA and a polycistronic mRNA of glvA-glvR-glvC. Primer extension analysis showed that both transcripts started at the same base (G) located 26 bp upstream of the 5' end of glvA. When glvR was placed under control of the spac promoter, expression of the glv operon was dependent upon the presence of isopropyl-beta-D-thiogalactopyranoside (IPTG). In regulatory studies, the promoter sequence of the glv operon was fused to lacZ and inserted into the amyE locus, and the resultant strain (AMGLV) was then transformed with a citrate-controlled glvR plasmid, pHYCM2VR. When cultured in Difco sporulation medium containing citrate, this transformant [AMGLV(pHYCM2VR)] expressed LacZ activity, but synthesis of LacZ was repressed by glucose. In an isogenic strain, [AMGLVCR(pHYCM2VR)], except for a mutation in the sequence of a catabolite-responsive element (cre), LacZ activity was expressed in the presence of citrate and glucose. Insertion of a citrate-controlled glvR plasmid at the amyE locus of ccpA(+) and ccpA mutant organisms yielded strains AMCMVR and AMCMVRCC, respectively. In the presence of both glucose and citrate, AMCMVR failed to express the glv operon, whereas under the same conditions high-level expression of both mRNA transcripts was found in strain AMCMVRCC. Collectively, our findings suggest that GlvR (the product of the glvR gene) is a positive regulator of the glv operon and that glucose exerts its effect via catabolite repression requiring both CcpA and cre.
巻・号 183(17)
ページ 5110-21
公開日 2001-9-1
DOI 10.1128/JB.183.17.5110-5121.2001
PMID 11489864
PMC PMC95387
MeSH Bacillus subtilis / genetics* Bacillus subtilis / metabolism Bacterial Proteins* Base Sequence Citric Acid / metabolism DNA-Binding Proteins / metabolism* Gene Expression Regulation, Enzymologic / genetics Glucose / metabolism Isopropyl Thiogalactoside / metabolism Lac Operon Maltose / genetics Maltose / metabolism* Operon* Repressor Proteins / metabolism* Ribosomal Proteins / metabolism* Sucrase-Isomaltase Complex / genetics Sucrase-Isomaltase Complex / metabolism Transcription, Genetic alpha-Glucosidases / genetics* alpha-Glucosidases / metabolism
IF 3.006
引用数 42
WOS 分野 MICROBIOLOGY
リソース情報
原核生物(枯草菌) MBS62 MBS63