3D6Y

Crystal structure of R275E mutant of BMRR bound to DNA and berberine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.227 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structures of BmrR-Drug Complexes Reveal a Rigid Multidrug Binding Pocket and Transcription Activation through Tyrosine Expulsion

Newberry, K.J.Huffman, J.L.Miller, M.C.Vazquez-Laslop, N.Neyfakh, A.A.Brennan, R.G.

(2008) J.Biol.Chem. 283: 26795-26804

  • DOI: 10.1074/jbc.M804191200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • BmrR is a member of the MerR family and a multidrug binding transcription factor that up-regulates the expression of the bmr multidrug efflux transporter gene in response to myriad lipophilic cationic compounds. The structural mechanism by which BmrR ...

    BmrR is a member of the MerR family and a multidrug binding transcription factor that up-regulates the expression of the bmr multidrug efflux transporter gene in response to myriad lipophilic cationic compounds. The structural mechanism by which BmrR binds these chemically and structurally different drugs and subsequently activates transcription is poorly understood. Here, we describe the crystal structures of BmrR bound to rhodamine 6G (R6G) or berberine (Ber) and cognate DNA. These structures reveal each drug stacks against multiple aromatic residues with their positive charges most proximal to the carboxylate group of Glu-253 and that, unlike other multidrug binding pockets, that of BmrR is rigid. Substitution of Glu-253 with either alanine (E253A) or glutamine (E253Q) results in unpredictable binding affinities for R6G, Ber, and tetraphenylphosphonium. Moreover, these drug binding studies reveal that the negative charge of Glu-253 is not important for high affinity binding to Ber and tetraphenylphosphonium but plays a more significant, but unpredictable, role in R6G binding. In vitro transcription data show that E253A and E253Q are constitutively active, and structures of the drug-free E253A-DNA and E253Q-DNA complexes support a transcription activation mechanism requiring the expulsion of Tyr-152 from the multidrug binding pocket. In sum, these data delineate the mechanism by which BmrR binds lipophilic, monovalent cationic compounds and suggest the importance of the redundant negative electrostatic nature of this rigid drug binding pocket that can be used to discriminate against molecules that are not substrates of the Bmr multidrug efflux pump.


    Organizational Affiliation

    Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030-4009, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure


Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Multidrug-efflux transporter 1 regulator
A
284Bacillus subtilis (strain 168)Mutation(s): 3 
Gene Names: bmrR (bmr1R)
Find proteins for P39075 (Bacillus subtilis (strain 168))
Go to UniProtKB:  P39075
Entity ID: 1
MoleculeChainsLengthOrganism
BMR promoter DNAB24N/A
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
BER
Query on BER

Download SDF File 
Download CCD File 
A
BERBERINE
C20 H18 N O4
YBHILYKTIRIUTE-UHFFFAOYSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
BERKd: 10300 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.7 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.227 
  • Space Group: P 43 2 2
Unit Cell:
Length (Å)Angle (°)
a = 106.330α = 90.00
b = 106.330β = 90.00
c = 146.750γ = 90.00
Software Package:
Software NamePurpose
SCALAdata scaling
CNSrefinement
MOSFLMdata reduction
EPMRphasing
ADSCdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-08-26
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Non-polymer description, Version format compliance