5h3r
Crystal Structure of mutant MarR C80S from E.coli complexed with operator DNACrystal Structure of mutant MarR C80S from E.coli complexed with operator DNA
Structural highlights
FunctionMARR_ECOLI Repressor of the marRAB operon which is involved in the activation of both antibiotic resistance and oxidative stress genes. Binds to the marO operator/promoter site. Publication Abstract from PubMedMultiple antibiotic resistance regulator (MarR) family proteins are widely conserved transcription factors that control bacterial resistance to antibiotics, environmental stresses, as well as the regulation of virulence determinants. Escherichia coli MarR, the prototype member of this family, has recently been shown to undergo copper(II)-catalyzed inter-dimer disulfide bond formation via a unique cysteine residue (Cys80) residing in its DNA-binding domain. However, despite extensive structural characterization of the MarR family proteins, the structural mechanism for DNA binding of this copper(II)-sensing MarR factor remains elusive. Here, we report the crystal structures of DNA-bound forms of MarR, which revealed a unique, concerted generation of two new helix-loop-helix motifs that facilitated MarR's DNA binding. Structural analysis and electrophoretic mobility shift assays (EMSA) show that the flexibility of Gly116 in the center of helix alpha5 and the extensive hydrogen-bonding interactions at the N-terminus of helix alpha1 together assist the reorientation of the wHTH domains and stabilize MarR's DNA-bound conformation. Structural characterization of the DNA-binding mechanism underlying the copper(II)-sensing MarR transcriptional regulator.,Zhu R, Hao Z, Lou H, Song Y, Zhao J, Chen Y, Zhu J, Chen PR J Biol Inorg Chem. 2017 Jul;22(5):685-693. doi: 10.1007/s00775-017-1442-7. Epub, 2017 Jan 25. PMID:28124121[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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