2KSS

NMR structure of Myxococcus xanthus antirepressor CarS1


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 

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This is version 1.1 of the entry. See complete history


Literature

A bacterial antirepressor with SH3 domain topology mimics operator DNA in sequestering the repressor DNA recognition helix.

Leon, E.Navarro-Aviles, G.Santiveri, C.M.Flores-Flores, C.Rico, M.Gonzalez, C.Murillo, F.J.Elias-Arnanz, M.Jimenez, M.A.Padmanabhan, S.

(2010) Nucleic Acids Res 38: 5226-5241

  • DOI: 10.1093/nar/gkq277
  • Primary Citation of Related Structures:  
    2KSS

  • PubMed Abstract: 
  • Direct targeting of critical DNA-binding elements of a repressor by its cognate antirepressor is an effective means to sequester the repressor and remove a transcription initiation block. Structural descriptions for this, though often proposed for bacter ...

    Direct targeting of critical DNA-binding elements of a repressor by its cognate antirepressor is an effective means to sequester the repressor and remove a transcription initiation block. Structural descriptions for this, though often proposed for bacterial and phage repressor-antirepressor systems, are unavailable. Here, we describe the structural and functional basis of how the Myxococcus xanthus CarS antirepressor recognizes and neutralizes its cognate repressors to turn on a photo-inducible promoter. CarA and CarH repress the carB operon in the dark. CarS, produced in the light, physically interacts with the MerR-type winged-helix DNA-binding domain of these repressors leading to activation of carB. The NMR structure of CarS1, a functional CarS variant, reveals a five-stranded, antiparallel beta-sheet fold resembling SH3 domains, protein-protein interaction modules prevalent in eukaryotes but rare in prokaryotes. NMR studies and analysis of site-directed mutants in vivo and in vitro unveil a solvent-exposed hydrophobic pocket lined by acidic residues in CarS, where the CarA DNA recognition helix docks with high affinity in an atypical ligand-recognition mode for SH3 domains. Our findings uncover an unprecedented use of the SH3 domain-like fold for protein-protein recognition whereby an antirepressor mimics operator DNA in sequestering the repressor DNA recognition helix to activate transcription.


    Related Citations: 
    • 1H, 13C, 15N backbone and side chain resonance assignments of a Myxococcus xanthus antirepressor with no known sequence homologues
      Leon, E., Navarro-Aviles, G., Flores, C., Elias-Arnanz, M., Gonzalez, C., Jimenez, M., Padmanabhan, S.
      (2009) Biomol NMR Assign 3: 37

    Organizational Affiliation

    Instituto de Química-Física Rocasolano, Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Carotenogenesis protein carS A106Myxococcus xanthusMutation(s): 0 
Gene Names: carS
Find proteins for Q06911 (Myxococcus xanthus)
Explore Q06911 
Go to UniProtKB:  Q06911
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 20 
  • Selection Criteria: target function 
  • OLDERADO: 2KSS Olderado

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-05-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance