S-box and T-box riboswitches and antisense RNA control a sulfur metabolic operon of Clostridium acetobutylicum.

ABSTRACT: The ubiGmccBA operon of Clostridium acetobutylicum is involved in methionine to cysteine conversion. We showed that its expression is controlled by a complex regulatory system combining several RNA-based mechanisms. Two functional convergent promoters associated with transcriptional antitermination systems, a cysteine-specific T-box and an S-box riboswitch, are located upstream of and downstream from the ubiG operon, respectively. Several antisense RNAs were synthesized from the downstream S-box-dependent promoter, resulting in modulation of the level of ubiG transcript and of MccB activity. In contrast, the upstream T-box system did not appear to play a major role in regulation, leaving antisense transcription as the major regulatory mechanism for the ubiG operon. The abundance of sense a

SUBMITTER: Andre G 

PROVIDER: S-EPMC2566862 | biostudies-literature | 2008 Oct

REPOSITORIES: biostudies-literature