6S / SsrS RNA

6S / SsrS RNA
Predicted secondary structure and sequence conservation of 6S
Identifiers
Symbol 6S
Rfam RF00013
Other data
RNA type Gene
Domain(s) Bacteria
SO 0000376

In molecular biology the 6S RNA is a noncoding RNA that was one of the first to be identified and sequenced.[1] What it does in the bacterial cell was unknown until recently. It consists of 184 nucleotides that fold into an extended hairpin structure with a large single-stranded internal bulge.

6S RNA specifically associates with RNA polymerase holoenzyme containing the sigma70 specificity factor. This interaction represses expression from sigma70-dependent promoters during stationary phase.[2] 6S RNA homologs have recently been identified in most bacterial genomes.[3][4] Many Gram-positive species have two copies of 6S RNA. In Bacillus subtilis, both copies appear to interact with RNA polymerase holoenzyme containing the housekeeping sigma factor and be expressed during different stages of growth. In many proteobacteria, 6S RNA may be processed from a transcript encoding homologs of the E. coli YgfA protein which is a putative methenyltetrahydrofolate synthetase. Diverged 6S RNAs have been identified in additional bacterial lineages.[5][6] The purD RNA motif has been experimentally shown to overlap with 6S RNA.[5]

References

  1. Brownlee GG (February 1971). "Sequence of 6S RNA of E. coli". Nature New Biol. 229 (5): 147–9. doi:10.1038/229147a0. PMID 4929322.
  2. Wassarman, KM; Storz G (2000). "6S RNA regulates E. coli RNA polymerase activity". Cell. 101 (6): 613623. doi:10.1016/S0092-8674(00)80873-9. PMID 10892648.
  3. Trotochaud, AE; Wassarman KM (2005). "A highly conserved 6S RNA structure is required for regulation of transcription". Nat Struct Mol Biol 12 (4): 313319. doi:10.1038/nsmb917. PMID 15793584.
  4. Barrick, JE; Sudarsan N; Weinberg Z; Ruzzo WL; Breaker RR (2005). "6S RNA is a widespread regulator of eubacterial RNA polymerase that resembles an open promoter". RNA. 11 (5): 774784. doi:10.1261/rna.7286705. PMC 1370762. PMID 15811922.
  5. 1 2 Sharma CM, Hoffmann S, Darfeuille F, et al. (February 2010). "The primary transcriptome of the major human pathogen Helicobacter pylori". Nature 464 (7286): 250–5. doi:10.1038/nature08756. PMID 20164839.
  6. Weinberg Z, Wang JX, Bogue J, et al. (March 2010). "Comparative genomics reveals 104 candidate structured RNAs from bacteria, archaea, and their metagenomes". Genome Biol 11 (3): R31. doi:10.1186/gb-2010-11-3-r31. PMC 2864571. PMID 20230605.

External links


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