3fdq
From Proteopedia
Recognition of AT-rich DNA binding sites by the MogR Repressor
Structural highlights
FunctionMOGR_LISMO Transcriptional repressor of flagellar motility genes, such as flaA, during extracellular growth at 37 degrees Celsius and during intracellular infection. Binds directly to the gene promoter region and probably prevents RNA polymerase binding. At low temperatures, MogR repression activity is modulated by the DegU response regulator in an unknown mechanism. Required for full virulence.[1] [2] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe MogR transcriptional repressor of the intracellular pathogen Listeria monocytogenes recognizes AT-rich binding sites in promoters of flagellar genes to downregulate flagellar gene expression during infection. We describe here the 1.8 A resolution crystal structure of MogR bound to the recognition sequence 5' ATTTTTTAAAAAAAT 3' present within the flaA promoter region. Our structure shows that MogR binds as a dimer. Each half-site is recognized in the major groove by a helix-turn-helix motif and in the minor groove by a loop from the symmetry-related molecule, resulting in a "crossover" binding mode. This oversampling through minor groove interactions is important for specificity. The MogR binding site has structural features of A-tract DNA and is bent by approximately 52 degrees away from the dimer. The structure explains how MogR achieves binding specificity in the AT-rich genome of L. monocytogenes and explains the evolutionary conservation of A-tract sequence elements within promoter regions of MogR-regulated flagellar genes. Recognition of AT-rich DNA binding sites by the MogR repressor.,Shen A, Higgins DE, Panne D Structure. 2009 May 13;17(5):769-77. PMID:19446532[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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