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6fi7
From Proteopedia
E.coli Sigma factor S (RpoS) Region 4
Structural highlights
FunctionRPOS_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 PubMedT7 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. See AlsoReferences
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