An alternative strategy for bacterial ribosome synthesis: Bacillus subtilis rRNA transcription regulation

• Published in: The EMBO journal 2004-11, Vol.23 (22), p.4473-4483
• Main Authors: Krásný, Libor, Gourse, Richard L
• Format: Article
• Language: English
• Subjects: B. subtilis; Bacillus subtilis; Bacillus subtilis - genetics; Bacteria; DNA-Directed RNA Polymerases - metabolism; E coli; EMBO09; EMBO23; Escherichia coli; Gene Expression Regulation, Bacterial; Genes, Bacterial; Genes, Reporter; GTP concentrations; Guanosine Tetraphosphate - metabolism; ppGpp; Promoter Regions, Genetic; promoters; Protein Biosynthesis; Ribosomes - genetics; Ribosomes - metabolism; RNA, Ribosomal - biosynthesis; RNA, Ribosomal - genetics; rRNA transcription; Transcription, Genetic
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1038/sj.emboj.7600423

As an approach to the study of rRNA synthesis in Gram‐positive bacteria, we characterized the regulation of the Bacillus subtilis rrnB and rrnO rRNA promoters. We conclude that B. subtilis and Escherichia coli use different strategies to control rRNA synthesis. In contrast to E. coli , it appears that the initiating NTP for transcription from B. subtilis rRNA promoters is GTP, promoter strength is determined primarily by the core promoter (−10/−35 region), and changes in promoter activity always correlate with changes in the intracellular GTP concentration. rRNA promoters in B. subtilis appear to be regulated by changes in the initiating NTP pools, but in some growth transitions, changes in rRNA promoter activity are also dependent on relA , which codes for ppGpp synthetase. In contrast to the situation for E. coli where ppGpp decreases rRNA promoter activity by directly inhibiting RNA polymerase, it appears that ppGpp may not inhibit B. subtilis RNA polymerase directly. Rather, increases in the ppGpp concentration might reduce the available GTP pools, thereby modulating rRNA promoter activity indirectly.