Biology:Mycobacterium tuberculosis sRNA

From HandWiki
Secondary structure of b55, one of the sRNAs experimentally confirmed in M. tuberculosis

Mycobacterium tuberculosis contains at least nine small RNA families in its genome.[1] The small RNA (sRNA) families were identified through RNomics – the direct analysis of RNA molecules isolated from cultures of Mycobacterium tuberculosis.[2][3] The sRNAs were characterised through RACE mapping and Northern blot experiments.[1] Secondary structures of the sRNAs were predicted using Mfold.[4]

sRNAPredict2 – a bioinformatics tool – suggested 56 putative sRNAs in M. tuberculosis, though these have yet to be verified experimentally.[5] Hfq protein homologues have yet to be found in M. tuberculosis;[6] an alternative pathway – potentially involving conserved C-rich motifs – has been theorised to enable trans-acting sRNA functionality.[1]

sRNAs were shown to have important physiological roles in M. tuberculosis. Overexpression of G2 sRNA, for example, prevented growth of M. tuberculosis and greatly reduced the growth of M. smegmatis; ASdes sRNA is thought to be a cis-acting regulator of a fatty acid desaturase (desA2) while ASpks is found with the open reading frame for Polyketide synthase-12 (pks12) and is an antisense regulator of pks12 mRNA.[1]

The sRNA ncrMT1302 was found to be flanked by the MT1302 and MT1303 open reading frames. MT1302 encodes an adenylyl cyclase that converts ATP to cAMP, the expression of ncrMT1302 is regulated by cAMP and pH.[7]

Mcr7 sRNA encoded by the mcr7 gene modulates translation of the tatC mRNA and impacts the activity of the Twin Arginine Translocation (Tat) protein secretion apparatus.[8]

npcTB_6715 is a first sRNA identified as a potential biomarker for the detection of MTB in patients.[9]

See also

References

  1. 1.0 1.1 1.2 1.3 "Identification of small RNAs in Mycobacterium tuberculosis". Molecular Microbiology 73 (3): 397–408. August 2009. doi:10.1111/j.1365-2958.2009.06777.x. PMID 19555452. 
  2. "RNomics in Escherichia coli detects new sRNA species and indicates parallel transcriptional output in bacteria". Nucleic Acids Research 31 (22): 6435–6443. November 2003. doi:10.1093/nar/gkg867. PMID 14602901. 
  3. "Detection of 5′- and 3′-UTR-derived small RNAs and cis-encoded antisense RNAs in Escherichia coli". Nucleic Acids Research 33 (3): 1040–1050. 2005. doi:10.1093/nar/gki256. PMID 15718303. 
  4. "Mfold web server for nucleic acid folding and hybridization prediction". Nucleic Acids Research 31 (13): 3406–3415. July 2003. doi:10.1093/nar/gkg595. PMID 12824337. 
  5. "Identification of 17 Pseudomonas aeruginosa sRNAs and prediction of sRNA-encoding genes in 10 diverse pathogens using the bioinformatic tool sRNAPredict2". Nucleic Acids Research 34 (12): 3484–3493. 2006. doi:10.1093/nar/gkl453. PMID 16870723. 
  6. "Predicted structure and phyletic distribution of the RNA-binding protein Hfq". Nucleic Acids Research 30 (17): 3662–3671. September 2002. doi:10.1093/nar/gkf508. PMID 12202750. 
  7. "A screen for non-coding RNA in Mycobacterium tuberculosis reveals a cAMP-responsive RNA that is expressed during infection". Gene 500 (1): 85–92. May 2012. doi:10.1016/j.gene.2012.03.044. PMID 22446041. 
  8. "The PhoP-dependent ncRNA Mcr7 modulates the TAT secretion system in Mycobacterium tuberculosis". PLOS Pathogens 10 (5): e1004183. May 2014. doi:10.1371/journal.ppat.1004183. PMID 24874799. 
  9. "RNomic identification and evaluation of npcTB_6715, a non-protein-coding RNA gene as a potential biomarker for the detection of Mycobacterium tuberculosis". Journal of Cellular and Molecular Medicine 21 (10): 2276–2283. October 2017. doi:10.1111/jcmm.13148. PMID 28756649. 

Further reading