3tgn
From Proteopedia
Crystal Structure of the zinc-dependent MarR Family Transcriptional Regulator AdcR in the Zn(II)-bound State
Structural highlights
Function[Q04I02_STRP2] Zinc-responsive regulator that acts both as a repressor and as an activator by regulating directly the promoters of its target genes. In the presence of zinc, directly represses the expression of the adcRCBA operon, of genes coding for a group of surface antigen zinc-binding pneumococcal histidine triad proteins (PhtA, PhtB, PhtD and PhtE), and of adcAII. Can also activate expression of adh.[1] [2] Publication Abstract from PubMedStreptococcus pneumoniae adhesin competence regulator (AdcR), the first metal-dependent member of the multiple antibiotic resistance regulator (MarR) family of proteins, represses the transcription of a high-affinity zinc-specific uptake transporter, a group of surface antigen zinc-binding pneumococcal histidine triad proteins (PhtA, PhtB, PhtD, and PhtE), and an AdcA homologue (AdcAII). The 2.0 A resolution structure of Zn(II)-bound AdcR reveals a highly helical two-fold-symmetric dimer with two distinct metal-binding sites per protomer. Zn(II) is tetrahedrally coordinated by E24, H42, H108, and H112 in what defines the primary sensing site in AdcR. Site 2 is a tetracoordinate site whose function is currently unknown. NMR methyl group perturbation experiments reveal that Zn(II) drives a global change in the structure of apo-AdcR that stabilizes a conformation that is compatible with DNA binding. This co-repression mechanism is unprecedented in MarR transcriptional regulators. Crystal Structure of the Zinc-Dependent MarR Family Transcriptional Regulator AdcR in the Zn(II)-Bound State.,Guerra AJ, Dann CE, Giedroc DP J Am Chem Soc. 2011 Nov 21. PMID:22085181[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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