Database accession: MF7000615
Name: MexR
PDB ID: 3mex
Experimental method: X-ray (2.10 Å)
Assembly: Homodimer
Source organism: Pseudomonas aeruginosa
Primary publication of the structure:
Chen H, Yi C, Zhang J, Zhang W, Ge Z, Yang CG, He C
Structural insight into the oxidation-sensing mechanism of the antibiotic resistance of regulator MexR.
(2010) EMBO Rep. 11: 685-90
PMID: 20616806
Abstract:
MexR functions as the primary regulator of the mexAB-oprM multidrug efflux expression in Pseudomonas aeruginosa. It has been shown that MexR senses oxidative stress by interprotomer disulphide bond formation between redox-active cysteines. This oxidation induces MexR to dissociate from the promoter DNA, thus activating the transcriptional expression of efflux pump genes. In this study, we present the crystal structure of MexR in its oxidized form at a resolution of 2.1 A. This crystal structure reveals the mechanism by which oxidative signal allosterically derepresses the MexR-controlled transcription activation.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
DNA-binding transcription repressor activity DNA-binding transcription repressor activity
identical protein binding identical protein binding
transcription cis-regulatory region binding transcription cis-regulatory region binding
Biological process:
negative regulation of DNA-templated transcription negative regulation of DNA-templated transcription
negative regulation of protein secretion negative regulation of protein secretion
negative regulation of transmembrane transport negative regulation of transmembrane transport
Cellular component:
protein-DNA complex protein-DNA complex
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, B
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Multidrug resistance operon repressor
Source organism: Pseudomonas aeruginosa
Length: 147 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMNYPVNPDLMPALMAVFQHVRTRIQSELDCQRLDLTPPDVHVLKLIDEQRGLNLQDLGRQMCRDKALITRKIRELEGRNLVRRERNPSDQRSFQLFLTDEGLAIHQHAEAIMSRVHDELFAPLTPVEQATLVHLLDQCLAAQPLEDI
UniProtKB AC: P52003 (positions: 1-142)
Coverage: 96%
Name: Multidrug resistance operon repressor
Source organism: Pseudomonas aeruginosa
Length: 147 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMNYPVNPDLMPALMAVFQHVRTRIQSELDCQRLDLTPPDVHVLKLIDEQRGLNLQDLGRQMCRDKALITRKIRELEGRNLVRRERNPSDQRSFQLFLTDEGLAIHQHAEAIMSRVHDELFAPLTPVEQATLVHLLDQCLAAQPLEDI
UniProtKB AC: P52003 (positions: 1-142)
Coverage: 96%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: Winged helix DNA-binding domain (MarR type I) transcriptional regulator
Evidence level: Direct evidence
Evidence coverage: Only some parts of the structure participates in mutual synergistic folding.
Complex Evidence:
The MarR-type family transcriptional regulator, NadR is dimeric in solution (SE-HPLC/MALLS) as other MarR faimily proteins (PMID:18272181). Compared to ligand-stabilized holo-NadR, apo-NadR displayed an intrinsic flexibility focused in the DNA-binding region (PMID:27105075). The structural features of several family members have been described, they all have two subdomains: there is a helix-turn-helix (HTH) DNA-binding domain plus dimerization helices that form an interlocked dimerization domain. Dimerization is mediated by helices α1, α5, and α6 from each monomer resulting in an interlocked, tight dimer burying a large, hydrophobic solvent-accessible surface area. The structure of the dimerization region reveals domain swapping, where α1 of one subunit is inserted between α5′ and α6′ of the other subunit and forms a coiled coil with helix α6′ (PMID:19586910). The DNA-binding elements contain helices α3-α4 and strands β1-β2 from each monomer (PMID:29794028, PMID:35367827).
Chain A:
N/A
Chain B:
N/A
Surface and contacts features:
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). Download the CIF file (.cif)
Download this entry's XML file (.xml)
Download this entry's JSON file (.json)
