Transcription initiation by sigma factors (WP2564)

Mycobacterium tuberculosis

Sigma factors are components of the RNA polymerase complex that are responsible for binding to the RNA polymerase complex, promoter recognition and separating DNA strands. The number of sigma factors is extremely diverse between bacteria, ranging from three in Helicobacter pylori to 63 in Streptomyces coelicolor. M. tuberculosis possesses 13 sigma factors, 10 of which are from the ECF sub-family, enabling this bacterium to cope with various environmental conditions


Andra Waagmeester , Egon Willighagen , Marianthi Kalafati , and Eric Weitz


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Mycobacterium tuberculosis



Pathway Ontology

regulatory pathway transcription pathway


Label Type Compact URI Comment
PhoY1 GeneProduct uniprot:P65718
Rv2884 GeneProduct uniprot:Q10808
Rv1823 GeneProduct uniprot:P64891
lrpI GeneProduct uniprot:O53750
lrpG GeneProduct uniprot:L7N534
RsfB GeneProduct uniprot:O69655
UsfX GeneProduct uniprot:P96892
RsfA GeneProduct uniprot:Q11035
SigA GeneProduct uniprot:P0A602
SigB GeneProduct uniprot:Q59563
SigG GeneProduct uniprot:L7N5U5
SigH GeneProduct uniprot:P66807
SigI GeneProduct uniprot:L7N4U5
SigJ GeneProduct uniprot:L0TCG5
SigK GeneProduct uniprot:O53730
SigL GeneProduct uniprot:Q7D9D4
SigM GeneProduct uniprot:O53590
SigC GeneProduct uniprot:P66809
SigD GeneProduct uniprot:P66811
SigE GeneProduct uniprot:O06289
SigF GeneProduct uniprot:Q7D5S2


  1. Mutation of the principal sigma factor causes loss of virulence in a strain of the Mycobacterium tuberculosis complex. Collins DM, Kawakami RP, de Lisle GW, Pascopella L, Bloom BR, Jacobs WR Jr. Proc Natl Acad Sci U S A. 1995 Aug 15;92(17):8036–40. PubMed Europe PMC Scholia
  2. Deciphering the biology of Mycobacterium tuberculosis from the complete genome sequence. Cole ST, Brosch R, Parkhill J, Garnier T, Churcher C, Harris D, et al. Nature. 1998 Jun 11;393(6685):537–44. PubMed Europe PMC Scholia
  3. Differential expression of 10 sigma factor genes in Mycobacterium tuberculosis. Manganelli R, Dubnau E, Tyagi S, Kramer FR, Smith I. Mol Microbiol. 1999 Jan;31(2):715–24. PubMed Europe PMC Scholia
  4. The Mycobacterium tuberculosis ECF sigma factor sigmaE: role in global gene expression and survival in macrophages. Manganelli R, Voskuil MI, Schoolnik GK, Smith I. Mol Microbiol. 2001 Jul;41(2):423–37. PubMed Europe PMC Scholia
  5. Novel Mycobacterium tuberculosis anti-sigma factor antagonists control sigmaF activity by distinct mechanisms. Beaucher J, Rodrigue S, Jacques PE, Smith I, Brzezinski R, Gaudreau L. Mol Microbiol. 2002 Sep;45(6):1527–40. PubMed Europe PMC Scholia
  6. Genes required for mycobacterial growth defined by high density mutagenesis. Sassetti CM, Boyd DH, Rubin EJ. Mol Microbiol. 2003 Apr;48(1):77–84. PubMed Europe PMC Scholia
  7. A postgenomic method for predicting essential genes at subsaturation levels of mutagenesis: application to Mycobacterium tuberculosis. Lamichhane G, Zignol M, Blades NJ, Geiman DE, Dougherty A, Grosset J, et al. Proc Natl Acad Sci U S A. 2003 Jun 10;100(12):7213–8. PubMed Europe PMC Scholia
  8. The extra cytoplasmic function sigma factor sigma(E) is essential for Mycobacterium tuberculosis virulence in mice. Manganelli R, Fattorini L, Tan D, Iona E, Orefici G, Altavilla G, et al. Infect Immun. 2004 May;72(5):3038–41. PubMed Europe PMC Scholia
  9. The Mycobacterium tuberculosis SigD sigma factor controls the expression of ribosome-associated gene products in stationary phase and is required for full virulence. Calamita H, Ko C, Tyagi S, Yoshimatsu T, Morrison NE, Bishai WR. Cell Microbiol. 2005 Feb;7(2):233–44. PubMed Europe PMC Scholia
  10. Identifying sigma factors in Mycobacterium smegmatis by comparative genomic analysis. Waagmeester A, Thompson J, Reyrat JM. Trends Microbiol. 2005 Nov;13(11):505–9. PubMed Europe PMC Scholia
  11. Mycobacterium tuberculosis SigF regulates genes encoding cell wall-associated proteins and directly regulates the transcriptional regulatory gene phoY1. Williams EP, Lee JH, Bishai WR, Colantuoni C, Karakousis PC. J Bacteriol. 2007 Jun;189(11):4234–42. PubMed Europe PMC Scholia
  12. Critical role of a single position in the -35 element for promoter recognition by Mycobacterium tuberculosis SigE and SigH. Song T, Song SE, Raman S, Anaya M, Husson RN. J Bacteriol. 2008 Mar;190(6):2227–30. PubMed Europe PMC Scholia
  13. Regulation of central metabolism genes of Mycobacterium tuberculosis by parallel feed-forward loops controlled by sigma factor E (σ(E)). Datta P, Shi L, Bibi N, Balázsi G, Gennaro ML. J Bacteriol. 2011 Mar;193(5):1154–60. PubMed Europe PMC Scholia
  14. High-resolution phenotypic profiling defines genes essential for mycobacterial growth and cholesterol catabolism. Griffin JE, Gawronski JD, Dejesus MA, Ioerger TR, Akerley BJ, Sassetti CM. PLoS Pathog. 2011 Sep;7(9):e1002251. PubMed Europe PMC Scholia