PDBsum entry 2jml

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protein links
Transcription PDB id
Protein chain
81 a.a. *
* Residue conservation analysis
PDB id:
Name: Transcription
Title: Solution structure of the n-terminal domain of cara represso
Structure: DNA binding domain/transcriptional regulator. Chain: a. Fragment: n-terminal domain, residues 1-78. Engineered: yes
Source: Myxococcus xanthus. Organism_taxid: 246197. Strain: dk 1622. Expressed in: escherichia coli bl21(de3). Expression_system_taxid: 469008.
NMR struc: 20 models
Authors: M.Jimenez,S.Padmanabhan,C.Gonzalez,M.C.Perez-Marin,M.Elias-A F.J.Murillo,M.Rico
Key ref: G.Navarro-Avilés et al. (2007). Structural basis for operator and antirepressor recognition by Myxococcus xanthus CarA repressor. Mol Microbiol, 63, 980-994. PubMed id: 17233828
20-Nov-06     Release date:   13-Feb-07    
Go to PROCHECK summary

Protein chain
Pfam   ArchSchema ?
Q1DDV9  (Q1DDV9_MYXXD) -  B12 binding domain/transcriptional regulator, MerR family
288 a.a.
81 a.a.
Key:    PfamA domain  Secondary structure  CATH domain

 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     regulation of transcription, DNA-dependent   1 term 
  Biochemical function     DNA binding     1 term  


Mol Microbiol 63:980-994 (2007)
PubMed id: 17233828  
Structural basis for operator and antirepressor recognition by Myxococcus xanthus CarA repressor.
G.Navarro-Avilés, M.A.Jiménez, M.C.Pérez-Marín, C.González, M.Rico, F.J.Murillo, M.Elías-Arnanz, S.Padmanabhan.
Blue light induces carotenogenesis in Myxococcus xanthus. The carB operon encodes all but one of the structural genes involved, and its expression is regulated by the CarA-CarS repressor-antirepressor pair. In the dark, CarA-operator binding represses carB. CarS, produced on illumination, interacts physically with CarA to dismantle the CarA-operator complex and activate carB. Both operator and CarS bind to the autonomously folded N-terminal domain of CarA, CarA(Nter), which in excess represses carB. Here, we report the NMR structure of CarA(Nter), and map residues that interact with operator and CarS by NMR chemical shift perturbations, and in vivo and in vitro analyses of site-directed mutants. We show CarA(Nter) adopts the winged-helix topology of MerR-family DNA-binding domains, and conserves the majority of the helix-turn-helix and wing contacts with DNA. Tellingly, helix alpha2 in CarA, a key element in operator DNA recognition, is also critical for interaction with CarS, implying that the CarA-CarS protein-protein and the CarA-operator protein-DNA interfaces overlap. Thus, binding of CarA to operator and to antirepressor are mutually exclusive, and CarA may discern structural features in the acidic CarS protein that resemble operator DNA. Repressor inactivation by occluding the DNA-binding region may be a recurrent mechanism of action for acidic antirepressors.

Literature references that cite this PDB file's key reference

  PubMed id Reference
21502508 J.M.Ortiz-Guerrero, M.C.Polanco, F.J.Murillo, S.Padmanabhan, and M.Elías-Arnanz (2011).
Light-dependent gene regulation by a coenzyme B12-based photoreceptor.
  Proc Natl Acad Sci U S A, 108, 7565-7570.  
21239214 M.Elías-Arnanz, S.Padmanabhan, and F.J.Murillo (2011).
Light-dependent gene regulation in nonphototrophic bacteria.
  Curr Opin Microbiol, 14, 128-135.  
20008065 E.D.Brutinel, C.A.Vakulskas, and T.L.Yahr (2010).
ExsD inhibits expression of the Pseudomonas aeruginosa type III secretion system by disrupting ExsA self-association and DNA binding activity.
  J Bacteriol, 192, 1479-1486.  
20410074 E.León, G.Navarro-Avilés, C.M.Santiveri, C.Flores-Flores, M.Rico, C.González, F.J.Murillo, M.Elías-Arnanz, M.A.Jiménez, and S.Padmanabhan (2010).
A bacterial antirepressor with SH3 domain topology mimics operator DNA in sequestering the repressor DNA recognition helix.
  Nucleic Acids Res, 38, 5226-5241.
PDB code: 2kss
19251845 D.García-Moreno, M.C.Polanco, G.Navarro-Avilés, F.J.Murillo, S.Padmanabhan, and M.Elías-Arnanz (2009).
A vitamin B12-based system for conditional expression reveals dksA to be an essential gene in Myxococcus xanthus.
  J Bacteriol, 191, 3108-3119.  
19240136 N.Tschowri, S.Busse, and R.Hengge (2009).
The BLUF-EAL protein YcgF acts as a direct anti-repressor in a blue-light response of Escherichia coli.
  Genes Dev, 23, 522-534.  
18310035 L.Galbis-Martínez, M.Galbis-Martínez, F.J.Murillo, and M.Fontes (2008).
An anti-antisigma factor in the response of the bacterium Myxococcus xanthus to blue light.
  Microbiology, 154, 895-904.  
17921255 G.Chen, P.D.Jeffrey, C.Fuqua, Y.Shi, and L.Chen (2007).
Structural basis for antiactivation in bacterial quorum sensing.
  Proc Natl Acad Sci U S A, 104, 16474-16479.
PDB code: 2q0o
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