rpoS mRNA encodes for the rpoS stress factor, sigma S (σS or σ38) in Escherichia coli and related bacteria, where DsrA in conjunction with the Sm like RNA binding protein, Hfq promote the translation of this rpoS mRNA.[1] The 5′ UTR of the rpoS mRNA forms a self-inhibitory stem loop that shields the shine-dalgarno sequence and therefore inhibits translation. The secondary structure of the 5′UTR was predicted by acetylation of ribose 2′-hydroxyls with NMIA and by using a secondary structure prediction program, RNAstructure.[2][3] DsrA stimulates rpoS translation by binding in the 5′UTR and causes the stem loop to open, exposing the ribosome binding site.
Site-directed mutagenesis and deletion analysis located an AAYAA motif identified upstream of the stem loop structure which is required for Hfq binding.[4] Comparative genomics has shown that this regulatory secondary structure is conserved across several gram-negative bacteria species.
References
edit- ^ Hengge-Aronis, R. (Sep 2002). "Signal Transduction and Regulatory Mechanisms Involved in Control of the σS (RpoS) Subunit of RNA Polymerase". Microbiology and Molecular Biology Reviews. 66 (3): 373–395, table 395 contents. doi:10.1128/MMBR.66.3.373-395.2002. ISSN 1092-2172. PMC 120795. PMID 12208995.
- ^ Merino, J.; Wilkinson, A.; Coughlan, L.; Weeks, M. (Mar 2005). "RNA Structure Analysis at Single Nucleotide Resolution by Selective 2′-Hydroxyl Acylation and Primer Extension (SHAPE)". Journal of the American Chemical Society. 127 (12): 4223–4231. doi:10.1021/ja043822v. ISSN 0002-7863. PMID 15783204.
- ^ Mathews, H.; Disney, D.; Childs, L.; Schroeder, J.; Zuker, M.; Turner, H. (May 2004). "Incorporating chemical modification constraints into a dynamic programming algorithm for prediction of RNA secondary structure". Proceedings of the National Academy of Sciences. 101 (19): 7287–7292. Bibcode:2004PNAS..101.7287M. doi:10.1073/pnas.0401799101. ISSN 0027-8424. PMC 409911. PMID 15123812.
- ^ Soper, J.; Woodson, A. (Sep 2008). "The rpoS mRNA leader recruits Hfq to facilitate annealing with DsrA sRNA". RNA. 14 (9): 1907–1917. doi:10.1261/rna.1110608. ISSN 1355-8382. PMC 2525945. PMID 18658123.