title: A regulatory protein that interferes with activator-stimulated transcription in bacteria.
abstract: Transcriptional activator proteins in bacteria often operate by interaction with the C-terminal domain of the alpha-subunit of RNA polymerase (RNAP). Here we report the discovery of an "anti-alpha" factor Spx in Bacillus subtilis that blocks transcriptional activation by binding to the alpha-C-terminal domain, thereby interfering with the capacity of RNAP to respond to certain activator proteins. Spx disrupts complex formation between the activator proteins ResD and ComA and promoter-bound RNAP, and it does so by direct interaction with the alpha-subunit. ResD- and ComA-stimulated transcription requires the proteolytic elimination of Spx by the ATP-dependent protease ClpXP. Spx represents a class of transcriptional regulators that inhibit activator-stimulated transcription by interaction with alpha.
authors.affiliation: Department of Environmental and Biomolecular Systems, OGI School of Science and Engineering, Oregon Health and Science University, Beaverton, OR 97006, USA.
authors.forename: Shunji
authors.initials: S
authors.lastname: Nakano
authors.forename: Michiko M
authors.initials: MM
authors.lastname: Nakano
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhang
authors.forename: Montira
authors.initials: M
authors.lastname: Leelakriangsak
authors.forename: Peter
authors.initials: P
authors.lastname: Zuber
mesh_terms: D004269:DNA, Bacterial / Q000235:genetics; D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000378:metabolism; D007700:Kinetics; D010957:Plasmids; D015534:Trans-Activators / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D015534:Trans-Activators; D012321:DNA-Directed RNA Polymerases