sigma54-RNA polymerase controls sigma70-dependent transcription from a non-overlapping divergent promoter.
2008 (English)In: Molecular microbiology, ISSN 1365-2958, Vol. 70, no 3, 709-23 p.Article in journal (Refereed) Published
Divergent transcription of a regulatory gene and a cognate promoter under its control is a common theme in bacterial regulatory circuits. This genetic organization is found for the dmpR gene that encodes the substrate-responsive specific regulator of the sigma(54)-dependent Po promoter, which controls (methyl)phenol catabolism. Here we identify the Pr promoter of dmpR as a sigma(70)-dependent promoter that is regulated by a novel mechanism in which sigma(54)-RNA polymerase occupancy of the non-overlapping sigma(54)-Po promoter stimulates sigma(70)-Pr output. In addition, we show that DmpR stimulates its own production through Po activity both in vivo and in vitro. Hence, the demonstrated regulatory circuit reveals a novel role for sigma(54)-RNA polymerase, namely regulation of a sigma(70)-dependent promoter, and a new mechanism that places a single promoter under dual control of two alternative forms of RNA polymerase. We present a model in which guanosine tetra-phosphate plays a major role in the interplay between sigma(54)- and sigma(70)-dependent transcription to ensure metabolic integration to couple sigma(70)-Pr output to both low-energy conditions and the presence of substrate.
Place, publisher, year, edition, pages
2008. Vol. 70, no 3, 709-23 p.
IdentifiersURN: urn:nbn:se:umu:diva-20504DOI: 10.1111/j.1365-2958.2008.06440.xPubMedID: 18786144OAI: oai:DiVA.org:umu-20504DiVA: diva2:208831