Crystal structure of a key regulator of virulence in Mycobacterium tuberculosis

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.198 

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EspR, a key regulator of Mycobacterium tuberculosis virulence, adopts a unique dimeric structure among helix-turn-helix proteins.

Rosenberg, O.S.Dovey, C.Tempesta, M.Robbins, R.A.Finer-Moore, J.S.Stroud, R.M.Cox, J.S.

(2011) Proc Natl Acad Sci U S A 108: 13450-13455

  • DOI: https://doi.org/10.1073/pnas.1110242108
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    EspR is a transcriptional regulator that activates the ESX-1 secretion system during Mycobacterium tuberculosis infection and is critical for pathogenesis. It is unique among DNA-binding proteins as it is secreted as part of a feedback regulatory loop that serves to mitigate transcriptional activity. Here we report the crystal structure of a functional EspR dimer at 2.5-Å resolution. The amino-terminal half of EspR is a helix-turn-helix (HTH) DNA-binding domain and the carboxy terminus consists of a dimerization domain with similarity to the SinR:SinI sporulation regulator of Bacillus subtilis. Surprisingly, the HTH domains of EspR are arranged in an unusual conformation in which they are splayed at an oblique angle to each other, suggesting that EspR binds DNA in a profoundly different way than most other known HTH regulators. By mapping the EspR binding sites in the espACD promoter, using both in vivo and in vitro binding assays, we show that the EspR operators are located unusually far from the promoter. The EspR dimer binds to these sites cooperatively, but the two "half-sites" contacted by each DNA recognition motif are separated by 177 base pairs. The distinctive structure of EspR and the exceptional arrangement of its operator contacts suggest that it could promote DNA looping in its target promoter. We hypothesize that direct DNA looping mediated by single-site binding of each EspR monomer may facilitate transcriptional control of this important virulence system.

  • Organizational Affiliation

    Department of Microbiology and Immunology, Program in Microbial Pathogenesis and Host Defense, University of California, San Francisco, CA 94158, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
ESX-1 secretion-associated regulator EspR
A, B, C, D, E
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R
135Mycobacterium tuberculosisMutation(s): 0 
Gene Names: espRMT3964Rv3849
Find proteins for P9WJB7 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WJB7 
Go to UniProtKB:  P9WJB7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP9WJB7
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B, C, D, E
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.232 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.198 
  • Space Group: P 32
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 148.49α = 90
b = 148.49β = 90
c = 129.671γ = 120
Software Package:
Software NamePurpose
PDB_EXTRACTdata extraction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-08-03
    Type: Initial release
  • Version 1.1: 2011-08-10
    Changes: Database references
  • Version 1.2: 2011-08-31
    Changes: Database references