2OPT

Crystal Structure of Apo ActR from Streptomyces coelicolor.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.195 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Crystal structures of the Streptomyces coelicolor TetR-like protein ActR alone and in complex with actinorhodin or the actinorhodin biosynthetic precursor (S)-DNPA.

Willems, A.R.Tahlan, K.Taguchi, T.Zhang, K.Lee, Z.Z.Ichinose, K.Junop, M.S.Nodwell, J.R.

(2008) J.Mol.Biol. 376: 1377-1387

  • DOI: 10.1016/j.jmb.2007.12.061
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Actinorhodin, an antibiotic produced by Streptomyces coelicolor, is exported from the cell by the ActA efflux pump. actA is divergently transcribed from actR, which encodes a TetR-like transcriptional repressor. We showed previously that ActR repress ...

    Actinorhodin, an antibiotic produced by Streptomyces coelicolor, is exported from the cell by the ActA efflux pump. actA is divergently transcribed from actR, which encodes a TetR-like transcriptional repressor. We showed previously that ActR represses transcription by binding to an operator from the actA/actR intergenic region. Importantly, actinorhodin itself or various actinorhodin biosynthetic intermediates can cause ActR to dissociate from its operator, leading to derepression. This suggests that ActR may mediate timely self-resistance to an endogenously produced antibiotic by responding to one of its biosynthetic precursors. Here, we report the structural basis for this precursor-mediated derepression with crystal structures of homodimeric ActR by itself and in complex with either actinorhodin or the actinorhodin biosynthetic intermediate (S)-DNPA [4-dihydro-9-hydroxy-1-methyl-10-oxo-3-H-naphtho-[2,3-c]-pyran-3-(S)-acetic acid]. The ligand-binding tunnel in each ActR monomer has a striking hydrophilic/hydrophobic/hydrophilic arrangement of surface residues that accommodate either one hexacyclic actinorhodin molecule or two back-to-back tricyclic (S)-DNPA molecules. Moreover, our work also reveals the strongest structural evidence to date that TetR-mediated antibiotic resistance may have been acquired from an antibiotic-producer organism.


    Organizational Affiliation

    Department of Biochemistry and Biomedical Sciences, McMaster University, 1200 Main Street West, Hamilton, Ontario, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
ActII protein
A, B
234Streptomyces coelicolorMutation(s): 0 
Gene Names: actII
Find proteins for Q53901 (Streptomyces coelicolor)
Go to UniProtKB:  Q53901
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.05 Å
  • R-Value Free: 0.247 
  • R-Value Work: 0.195 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 55.648α = 90.00
b = 79.957β = 90.00
c = 104.027γ = 90.00
Software Package:
Software NamePurpose
CNSphasing
REFMACrefinement
HKL-2000data scaling
HKL-2000data reduction
HKL-2000data collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-02-05
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Derived calculations, Version format compliance