Database accession: MF7000244
Name: MarR
PDB ID: 3bpx
Experimental method: X-ray (1.95 Å)
Assembly: Homodimer
Source organism: Methanothermobacter thermautotrophicus
Primary publication of the structure:
Saridakis V, Shahinas D, Xu X, Christendat D
Structural insight on the mechanism of regulation of the MarR family of proteins: high-resolution crystal structure of a transcriptional repressor from Methanobacterium thermoautotrophicum.
(2008) J. Mol. Biol. 377: 655-67
PMID: 18272181
Abstract:
Transcriptional regulators belonging to the MarR family are characterized by a winged-helix DNA binding domain. These transcriptional regulators regulate the efflux and influx of phenolic agents in bacteria and archaea. In Escherichia coli, MarR regulates the multiple antibiotic resistance operon and its inactivation produces a multiple antibiotic resistance phenotype. In some organisms, active efflux of drug compounds will produce a drug resistance phenotype, whereas in other organisms, active influx of chlorinated hydrocarbons results in their rapid degradation. Although proteins in the MarR family are regulators of important biological processes, their mechanism of action is not well understood and structural information about how phenolic agents regulate the activity of these proteins is lacking. This article presents the three-dimensional structure of a protein of the MarR family, MTH313, in its apo form and in complex with salicylate, a known inactivator. A comparison of these two structures indicates that the mechanism of regulation involves a large conformational change in the DNA binding lobe. Electrophoretic mobility shift assay and biophysical analyses further suggest that salicylate inactivates MTH313 and prevents it from binding to its promoter region.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
DNA-binding transcription factor activity DNA-binding transcription factor activity
Biological process: not assigned
Cellular component: not assigned
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: Transcriptional regulator
Source organism: Methanothermobacter thermautotrophicus
Length: 146 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMDRDIPLKGLLSIILRSHRVFIGRELGHLNLTDAQVACLLRIHREPGIKQDELATFFHVDKGTIARTLRRLEESGFIEREQDPENRRRYILEVTRRGEEIIPLILKVEERWEDLLFRDFTEDERKLFRKMCRRLAEEAVRMRGEWR
UniProtKB AC: O26413 (positions: 1-145)
Coverage: 99%
Name: Transcriptional regulator
Source organism: Methanothermobacter thermautotrophicus
Length: 146 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMDRDIPLKGLLSIILRSHRVFIGRELGHLNLTDAQVACLLRIHREPGIKQDELATFFHVDKGTIARTLRRLEESGFIEREQDPENRRRYILEVTRRGEEIIPLILKVEERWEDLLFRDFTEDERKLFRKMCRRLAEEAVRMRGEWR
UniProtKB AC: O26413 (positions: 4-141)
Coverage: 94%
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)
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