PMID:11222598

From omp dev
Jump to: navigation, search
Citation

Sledjeski, DD, Whitman, C and Zhang, A (2001) Hfq is necessary for regulation by the untranslated RNA DsrA.J. Bacteriol. 183:1997-2005

Abstract

DsrA is an 85-nucleotide, untranslated RNA that has multiple regulatory activities at 30 degrees C. These activities include the translational regulation of RpoS and H-NS, global transcriptional regulators in Escherichia coli. Hfq is an E. coli protein necessary for the in vitro and in vivo replication of the RNA phage Qbeta. Hfq also plays a role in the degradation of numerous RNA transcripts. Here we show that an hfq mutant strain is defective for DsrA-mediated regulation of both rpoS and hns. The defect in rpoS expression can be partially overcome by overexpression of DsrA. Hfq does not regulate the transcription of DsrA, and DsrA does not alter the accumulation of Hfq. However, in an hfq mutant, chromosome-expressed DsrA was unstable (half-life of 1 min) and truncated at the 3' end. When expressed from a multicopy plasmid, DsrA was stable in both wild-type and hfq mutant strains, but it had only partial activity in the hfq mutant strain. Purified Hfq binds DsrA in vitro. These results suggest that Hfq acts as a protein cofactor for the regulatory activities of DsrA by either altering the structure of DsrA or forming an active RNA-protein complex.

Links

PubMed Online version:10.1128/JB.183.6.1997-2005.2001

Keywords

Bacterial Proteins; Carrier Proteins; Chromosomes, Bacterial; DNA-Binding Proteins; Escherichia coli; Escherichia coli Proteins; Gene Expression Regulation, Bacterial; Host Factor 1 Protein; Integration Host Factors; Lac Operon; Mutation; Plasmids; Protein Biosynthesis; RNA, Untranslated; Recombinant Fusion Proteins; Sigma Factor; Transcription, Genetic

Main Points of the Paper

Please summarize the main points of the paper.

Materials and Methods Used

Please list the materials and methods used in this paper (strains, plasmids, antibodies, etc).

Phenotype Annotations

See Help:AnnotationTable for details on how to edit this table.
<protect>

Phenotype of Taxon Information Genotype Information (if known) Condition Information OMP ID OMP Term Name ECO ID ECO Term Name Notes Status

</protect>

Notes

References

See Help:References for how to manage references in omp dev.