Gene-regulatory modules in Escherichia coli: nucleoprotein complexes formed by cAMP-CRP and CytR at the nupG promoter

Molecular Microbiology
H PedersenP Valentin-Hansen

Abstract

Repression by CytR depends on the formation of nucleoprotein complexes in which the CytR repressor and the cAMP-CRP activator complex bind co-operatively to the DNA. Transcription initiation from CytR-regulated promoters requires cAMP-CRP; therefore, the cAMP-CRP complex functions both as an activator and as a co-repressor in these promoters. Another interesting aspect of the CytR regulon is that each promoter appears to have individual features. Therefore, structural and functional rules governing the formation of repression and activation complexes in one promoter may not be valid for other promoters of the CytR regulon. Here we show that the Escherichia coli nupG gene contains one CytR- and four CRP-binding sites in the control region. Notably, the architecture of the CytR binding site is different from previously described targets. In addition, the CytR repressor triggers a DNA repositioning of a cAMP-CRP complex in the -35 region upon binding to its operator. Thus, formation of the repression and activation complexes at the nupG promoter involves different subsets of CRP-binding sites. These findings show that the bacterium uses positive and negative regulatory modules to differentially control the expression of CytR- and ...Continue Reading

Citations

Jun 1, 2002·Gene·Siddhartha RoySankar Adhya
Sep 17, 1996·Proceedings of the National Academy of Sciences of the United States of America·P B RasmussenP Valentin-Hansen
Aug 19, 2007·Journal of Molecular Microbiology and Biotechnology·Masahiro KakehiShinichi Sugimoto
Dec 5, 2006·PLoS Computational Biology·Rutger HermsenPieter Rein ten Wolde
Jun 7, 2003·Molecular Microbiology·Anne-Marie HansenDing Jun Jin
Jul 4, 1997·The Journal of Biological Chemistry·C S BarbierD F Senear
May 18, 2018·PloS One·Haythem LatifBernhard O Palsson
Sep 1, 2008·EcoSal Plus·Kaj Frank JensenMartin WillemoËs

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