Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Igarashi et al. (K. Igarashi, N. Fujita, and A. Ishihama, Nucleic Acids Res. 17:8755-8765, 1989) reported that the omega (omega) subunit of Escherichia coli RNA polymerase was required for stringent control as judged by in vitro transcription assays in the presence and absence of guanosine 3',5'-bispyrophosphate (ppGpp). This conclusion predicts that a deletion of the omega gene (designated rpoZ or spoS) should show a relaxed RNA control phenotype in vivo. However, we find that wild-type stringent control of stable RNA accumulation is unaffected by a spoS null allele that abolishes cellular production of the omega protein. We conclude that omega protein is not necessary for the operation of the stringent RNA control response.
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PMID:The omega subunit of Escherichia coli K-12 RNA polymerase is not required for stringent RNA control in vivo. 171 Oct 31

The omega protein is a peptide found in near-stoichiometric levels in highly purified Escherichia coli RNA polymerase. In order to determine the binding site of omega to RNA polymerase, we cross-linked omega to RNA polymerase with the hetero-bifunctional cross-linker N-hydroxysuccinimidyl 4-azidobenzoate and analyzed for cross-linked partners using antibodies raised against each of the subunits. Our analysis indicates that omega cross-links predominantly with the beta' subunit, while a very low level of cross-linking was detected to the alpha subunit. We did not detect cross-linking to either the sigma 70 or the beta subunits. This report demonstrates the utility of combining cross-linking and immunological techniques to determine interactions between RNA polymerase subunits.
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PMID:Cross-linking of Escherichia coli RNA polymerase subunits: identification of beta' as the binding site of omega. 821 87

Evidence obtained in both eukaryotes and prokaryotes indicates that arbitrary contacts between DNA-bound proteins and components of the transcriptional machinery can activate transcription. Here we demonstrate that the Escherichia coli omega protein, which copurifies with RNA polymerase, can function as a transcriptional activator when linked covalently to a DNA-binding protein. We show further that omega can function as an activation target when this covalent linkage is replaced by a pair of interacting polypeptides fused to the DNA-binding protein and to omega, respectively. Our findings imply that the omega protein is associated with RNA polymerase holoenzyme in vivo, and provide support for the hypothesis that contact between a DNA-bound protein and any component of E. coli RNA polymerase can activate transcription.
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PMID:Conversion of the omega subunit of Escherichia coli RNA polymerase into a transcriptional activator or an activation target. 949 8

We have cloned the rpoZ gene, encoding RNA polymerase omega protein, by PCR approach from the deep-sea piezophilic and psychrophilic bacterium, Shewanella violacea strain DSS12. The cloned gene, 285bp in length, was found to encode a protein consisting of 94 amino acid residues with a molecular mass of 10,327 Da. Significant homology was evident comparing the RpoZ protein of S. violacea with that of Shewanella oneidensis (69% identity), Vibrio cholerae (65% identity), Escherichia coli K-12 (64% identity) and Haemophilus influenzae (61% identity). From the Northern blot analysis, S. violacea rpoZ gene was expressed constitutively under pressure conditions of 0.1, 30 and 50MPa. We constructed expression plasmid to overproduce the RpoZ protein and transformed into E. coli JM109 as a host of overproduction. Upon induction, the recombinant protein encoded by plasmid pQrpoZ was overexpressed and purified using Ni2+ affinity column.
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PMID:Cloning and overproduction of the rpoZ gene encoding an RNA polymerase omega subunit from a deep-sea piezophilic Shewanella violacea strain DSS12. 1534 66