The alpha subunit of RNA polymerase specifically inhibits expression of the porin genes ompF and ompC in vivo and in vitro in Escherichia coli.
Overproduction of the alpha subunit of RNA polymerase in Escherichia coli resulted in inhibition of transcription of two osmoregulated porin genes, ompF and ompC, but not of constitutively expressed housekeeping genes. Overproduction of the sigma subunit did not have any inhibitory effects. The specific inhibitory effect of the alpha subunit was also found to depend upon the OmpR protein, the transcriptional activator for ompF and ompC. These results are in general agreement with other biochemical and genetic evidence suggesting that the alpha subunit is the subunit of RNA polymerase that directly interacts with certain transcriptional activators to initiate transcription.
Bowrin
V
V
Department of Biochemistry, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey at Rutgers, Piscataway 08854.
Brissette
R
R
Tsung
K
K
Inouye
M
M
D001425:Bacterial Outer Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry* / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial / Q000235:genetics*; D005798:Genes, Bacterial / Q000235:genetics; D012329:RNA, Bacterial / Q000032:analysis; D014158:Transcription, Genetic
D001425:Bacterial Outer Membrane Proteins; D012329:RNA, Bacterial; D012321:DNA-Directed RNA Polymerases