yveB, Encoding endolevanase LevB, is part of the sacB-yveB-yveA levansucrase tricistronic operon in Bacillus subtilis.
Transcription of sacB, yveB and yveA, three clustered genes on the Bacillus subtilis chromosome, is simultaneously induced by sucrose. Northern blotting analyses with specific probes showed three distinct mRNAs: a monocistronic 1.7 kb sacB mRNA, a bicistronic 3.3 kb sacB-yveB mRNA and a tricistronic 4.9 kb sacB-yveB-yveA mRNA. These results indicate that sacB, encoding levansucrase, is the proximal gene of a sucrose-inducible operon that includes the two other genes. The yield of the full-length transcript is lower than that of the bicistronic transcript, whose yield is itself lower than that of the monocistronic transcript. This suggested that the 3' terminal parts of sacB and yveB genes worked as internal terminator structures. The protein encoded by yveB, which remains anchored to the membrane, displays an endolevanase activity, which, coupled with exolevanase activity of SacB, leads to a complete degradation of levan, a branched fructosyl polymer. It is proposed to rename yveB as levB.
Pereira
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Y
Institut Jacques Monod, Laboratoire Génétique et Membranes, CNRS-Universités Paris 6 et Paris 7, Tour 43, 2 place Jussieu, 75251 Paris Cedex 05, France.
Petit-Glatron
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MF
Chambert
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R
D001412:Bacillus subtilis / Q000201:enzymology / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D002451:Cell Compartmentation; D004790:Enzyme Induction; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006026:Glycoside Hydrolases / Q000235:genetics*; D006602:Hexosyltransferases / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D009876:Operon; D012329:RNA, Bacterial / Q000302:isolation & purification; D012333:RNA, Messenger / Q000302:isolation & purification; D013395:Sucrose / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D013395:Sucrose; D006602:Hexosyltransferases; C021513:levansucrase; D006026:Glycoside Hydrolases; C444424:YveB protein, Bacillus subtilis