Transcripts of the genes sacB, amyE, sacC and csn expressed in Bacillus subtilis under the control of the 5' untranslated sacR region display different stabilities that can be modulated

• Published in: Microbiology (Society for General Microbiology) Vol. 147; no. 5; pp. 1331 - 1341
• Main Authors: Pereira, Yannick, Chambert, Regis, Leloup, Laurence, Daguer, Jean-Pierre, Petit-Glatron, Marie-Francoise
• Format: Journal Article
• Language: English
• Published: Reading Soc General Microbiol 01.05.2001; Society for General Microbiology
• Subjects: 5' Untranslated Regions; alpha-Amylases - biosynthesis; alpha-Amylases - genetics; amyE gene; Bacillus subtilis; Bacillus subtilis - genetics; Bacillus subtilis - metabolism; Bacterial Proteins; Bacteriology; Biological and medical sciences; Blotting, Northern; csn gene; Fundamental and applied biological sciences. Psychology; Genetics; Glycoside Hydrolases - biosynthesis; Glycoside Hydrolases - genetics; Hexosyltransferases - biosynthesis; Hexosyltransferases - genetics; Kinetics; Microbiology; mRNA; Nucleic Acid Conformation; Protein Biosynthesis; Ribosomes - metabolism; RNA, Messenger - analysis; RNA, Messenger - metabolism; sacB gene; sacC gene; sacR gene; Transcription, Genetic; Biodegradation; Molecular processing; Structure stability; Enzyme; Bacillus subtilis; Levansucrase; Transferases; Glycosyltransferases; Genetical translation; Bacillaceae; Gene expression; Secondary structure; Regulation(control); Messenger RNA; Bacillales; Glycosidases; Chitosanase; Bacteria; Hydrolases; Hexosyltransferases; Kinetics; α-Amylase; O-Glycosidases; Levanase
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/00221287-147-5-1331

Institut Jacques Monod CNRS, Universités Paris 6-7, Laboratoire Génétique et Membranes, Tour 43, 2 place Jussieu 75251, Paris Cedex 05, France 1 Author for correspondence: Marie-Françoise Petit-Glatron. Tel: +33 1 44 27 47 19. Fax: +33 1 44 27 59 94. e-mail: glatron{at}ccr.jussieu.fr When Bacillus subtilis levanase (SacC), -amylase (AmyE) and chitosanase (Csn) structural genes were expressed under the regulated control of sacR , the inducible levansucrase (SacB) leader region in a degU32 (Hy) mutant, it was observed that the production yields of the various extracellular proteins were quite different. This is mainly due to differences in the stabilities of their corresponding mRNAs which lead to discrepancies between the steady-state level of mRNA of sacB and csn on the one hand and amyE and sacC on the other. In contrast to levansucrase mRNA, the decay curves of -amylase and levanase mRNAs obtained by Northern blotting analysis did not match the decay curves of their functional mRNA. This suggested that only a part of the population of the amyE and sacC transcripts was fully translated, while the others were possibly poorly bound to ribosomes and thus were only partially translated or not at all and consequently submitted to rapid endonuclease degradation. This hypothesis was substantiated by the finding that the introduction of a Shine–Dalgarno sequence upstream from the ribosome-binding site in the sacC transcript resulted in a fourfold increase in both the half-life of this transcript and the production of levanase. An additional cause of low-level levanase production is the premature release of mRNA by the polymerase. It was attempted to correlate this event with internal secondary structures of sacC mRNA. Keywords: mRNA decay, exocellular proteins, sacR , 5' mRNA stabilizer Abbreviations: SD, Shine–Dalgarno a Present address: Department of Plant Pathology, University of California, Davis, California 95616, USA.