| Structural highlights
Function
[RPOS_ECOLI] Sigma factors are initiation factors that promote the attachment of RNA polymerase to specific initiation sites and are then released. This sigma factor is the master transcriptional regulator of the stationary phase and the general stress response. Controls, positively or negatively, the expression of several hundred genes, which are mainly involved in metabolism, transport, regulation and stress management.[HAMAP-Rule:MF_00959][1] [2] [3] [4] [5] Protects stationary phase cells from killing induced by endoribonuclease MazF.[6]
Publication Abstract from PubMed
T7 development in Escherichia coli requires the inhibition of the housekeeping form of the bacterial RNA polymerase (RNAP), Esigma(70), by two T7 proteins: Gp2 and Gp5.7. Although the biological role of Gp2 is well understood, that of Gp5.7 remains to be fully deciphered. Here, we present results from functional and structural analyses to reveal that Gp5.7 primarily serves to inhibit Esigma(S), the predominant form of the RNAP in the stationary phase of growth, which accumulates in exponentially growing E. coli as a consequence of the buildup of guanosine pentaphosphate [(p)ppGpp] during T7 development. We further demonstrate a requirement of Gp5.7 for T7 development in E. coli cells in the stationary phase of growth. Our finding represents a paradigm for how some lytic phages have evolved distinct mechanisms to inhibit the bacterial transcription machinery to facilitate phage development in bacteria in the exponential and stationary phases of growth.
T7 phage factor required for managing RpoS in Escherichia coli.,Tabib-Salazar A, Liu B, Barker D, Burchell L, Qimron U, Matthews SJ, Wigneshweraraj S Proc Natl Acad Sci U S A. 2018 May 22. pii: 1800429115. doi:, 10.1073/pnas.1800429115. PMID:29789383[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Patten CL, Kirchhof MG, Schertzberg MR, Morton RA, Schellhorn HE. Microarray analysis of RpoS-mediated gene expression in Escherichia coli K-12. Mol Genet Genomics. 2004 Dec;272(5):580-91. Epub 2004 Nov 19. PMID:15558318 doi:http://dx.doi.org/10.1007/s00438-004-1089-2
- ↑ Weber H, Polen T, Heuveling J, Wendisch VF, Hengge R. Genome-wide analysis of the general stress response network in Escherichia coli: sigmaS-dependent genes, promoters, and sigma factor selectivity. J Bacteriol. 2005 Mar;187(5):1591-603. PMID:15716429 doi:http://dx.doi.org/10.1128/JB.187.5.1591-1603.2005
- ↑ Rahman M, Hasan MR, Oba T, Shimizu K. Effect of rpoS gene knockout on the metabolism of Escherichia coli during exponential growth phase and early stationary phase based on gene expressions, enzyme activities and intracellular metabolite concentrations. Biotechnol Bioeng. 2006 Jun 20;94(3):585-95. PMID:16511888 doi:http://dx.doi.org/10.1002/bit.20858
- ↑ Maciag A, Peano C, Pietrelli A, Egli T, De Bellis G, Landini P. In vitro transcription profiling of the sigmaS subunit of bacterial RNA polymerase: re-definition of the sigmaS regulon and identification of sigmaS-specific promoter sequence elements. Nucleic Acids Res. 2011 Jul;39(13):5338-55. doi: 10.1093/nar/gkr129. Epub 2011, Mar 11. PMID:21398637 doi:http://dx.doi.org/10.1093/nar/gkr129
- ↑ Tanaka K, Takayanagi Y, Fujita N, Ishihama A, Takahashi H. Heterogeneity of the principal sigma factor in Escherichia coli: the rpoS gene product, sigma 38, is a second principal sigma factor of RNA polymerase in stationary-phase Escherichia coli. Proc Natl Acad Sci U S A. 1993 Apr 15;90(8):3511-5. PMID:8475100
- ↑ Kolodkin-Gal I, Engelberg-Kulka H. The stationary-phase sigma factor sigma(S) is responsible for the resistance of Escherichia coli stationary-phase cells to mazEF-mediated cell death. J Bacteriol. 2009 May;191(9):3177-82. doi: 10.1128/JB.00011-09. Epub 2009 Feb 27. PMID:19251848 doi:http://dx.doi.org/10.1128/JB.00011-09
- ↑ Tabib-Salazar A, Liu B, Barker D, Burchell L, Qimron U, Matthews SJ, Wigneshweraraj S. T7 phage factor required for managing RpoS in Escherichia coli. Proc Natl Acad Sci U S A. 2018 May 22. pii: 1800429115. doi:, 10.1073/pnas.1800429115. PMID:29789383 doi:http://dx.doi.org/10.1073/pnas.1800429115
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