title: Post-transcriptional regulation of NifA expression by Hfq and RNase E complex in Rhizobium leguminosarum bv. viciae.
abstract: NifA is the general transcriptional activator of nitrogen fixation genes in diazotrophic bacteria. In Rhizobium leguminosarum bv. viciae strain 8401/pRL1JI, the NifA gene is part of a gene cluster (fixABCXNifAB). In this study, results showed that in R. leguminosarum bv.viciae 8401/pRL1JI, host factor required (Hfq), and RNase E were involved in the post-transcriptional regulation of NifA expression. It was found that Hfq-dependent RNase E cleavage of NifA mRNA was essential for NifA translation. The cleavage site is located at 32 nucleotides upstream of the NifA translational start codon. A possible explanation based on predicted RNA secondary structure of the NifA 5'-untranslated region was that the cleavage made ribosome-binding sites accessible for translation.
authors.affiliation: State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China.
authors.forename: Yinghua
authors.initials: Y
authors.lastname: Zhang
authors.forename: Guofan
authors.initials: G
authors.lastname: Hong
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D004722:Endoribonucleases / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology*; D035001:Host Factor 1 Protein / Q000378:metabolism*; D012231:Rhizobium / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*; D015533:Transcriptional Activation / Q000502:physiology*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C087373:Hfq protein, E coli; D035001:Host Factor 1 Protein; C061338:NifA protein, Bacteria; D014157:Transcription Factors; D004722:Endoribonucleases; C022537:ribonuclease E