6AYI

Escherichia coli GusR


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.09 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis for the regulation of beta-glucuronidase expression by human gut Enterobacteriaceae.

Little, M.S.Pellock, S.J.Walton, W.G.Tripathy, A.Redinbo, M.R.

(2018) Proc. Natl. Acad. Sci. U.S.A. 115: E152-E161

  • DOI: 10.1073/pnas.1716241115
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The gut microbiota harbor diverse β-glucuronidase (GUS) enzymes that liberate glucuronic acid (GlcA) sugars from small-molecule conjugates and complex carbohydrates. However, only the Enterobacteriaceae family of human gut-associated Proteobacteria m ...

    The gut microbiota harbor diverse β-glucuronidase (GUS) enzymes that liberate glucuronic acid (GlcA) sugars from small-molecule conjugates and complex carbohydrates. However, only the Enterobacteriaceae family of human gut-associated Proteobacteria maintain a GUS operon under the transcriptional control of a glucuronide repressor, GusR. Despite its potential importance in Escherichia, Salmonella, Klebsiella, Shigella, and Yersinia opportunistic pathogens, the structure of GusR has not been examined. Here, we explore the molecular basis for GusR-mediated regulation of GUS expression in response to small-molecule glucuronides. Presented are 2.1-Å-resolution crystal structures of GusRs from Escherichia coli and Salmonella enterica in complexes with a glucuronide ligand. The GusR-specific DNA operator site in the regulatory region of the E. coli GUS operon is identified, and structure-guided GusR mutants pinpoint the residues essential for DNA binding and glucuronide recognition. Interestingly, the endobiotic estradiol-17-glucuronide and the xenobiotic indomethacin-acyl-glucuronide are found to exhibit markedly differential binding to these GusR orthologs. Using structure-guided mutations, we are able to transfer E. coli GusR's preferential DNA and glucuronide binding affinity to S. enterica GusR. Structures of putative GusR orthologs from GUS-encoding Firmicutes species also reveal functionally unique features of the Enterobacteriaceae GusRs. Finally, dominant-negative GusR variants are validated in cell-based studies. These data provide a molecular framework toward understanding the control of glucuronide utilization by opportunistic pathogens in the human gut.


    Organizational Affiliation

    Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3290.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
HTH-type transcriptional regulator UidR
A, B, C, D
199Escherichia coli O157:H7Mutation(s): 0 
Gene Names: uidR
Find proteins for P0ACT8 (Escherichia coli O157:H7)
Go to UniProtKB:  P0ACT8
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
C3G
Query on C3G

Download SDF File 
Download CCD File 
A, B, C, D
4-nitrophenyl beta-D-glucopyranosiduronic acid
C12 H13 N O9
QSUILVWOWLUOEU-GOVZDWNOSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.09 Å
  • R-Value Free: 0.221 
  • R-Value Work: 0.187 
  • Space Group: P 2 21 21
Unit Cell:
Length (Å)Angle (°)
a = 50.997α = 90.00
b = 106.744β = 90.00
c = 135.249γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-12-20
    Type: Initial release
  • Version 1.1: 2018-01-03
    Type: Database references
  • Version 1.2: 2018-01-17
    Type: Database references