4GYR

Granulibacter bethesdensis allophanate hydrolase apo


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.307 
  • R-Value Work: 0.256 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The Structure of Allophanate Hydrolase from Granulibacter bethesdensis Provides Insights into Substrate Specificity in the Amidase Signature Family.

Lin, Y.St Maurice, M.

(2013) Biochemistry 52: 690-700

  • DOI: 10.1021/bi301242m
  • Primary Citation of Related Structures:  4GYS

  • PubMed Abstract: 
  • Allophanate hydrolase (AH) catalyzes the hydrolysis of allophanate, an intermediate in atrazine degradation and urea catabolism pathways, to NH(3) and CO(2). AH belongs to the amidase signature family, which is characterized by a conserved block of 1 ...

    Allophanate hydrolase (AH) catalyzes the hydrolysis of allophanate, an intermediate in atrazine degradation and urea catabolism pathways, to NH(3) and CO(2). AH belongs to the amidase signature family, which is characterized by a conserved block of 130 amino acids rich in Gly and Ser and a Ser-cis-Ser-Lys catalytic triad. In this study, the first structures of AH from Granulibacter bethesdensis were determined, with and without the substrate analogue malonate, to 2.2 and 2.8 Å, respectively. The structures confirm the identity of the catalytic triad residues and reveal an altered dimerization interface that is not conserved in the amidase signature family. The structures also provide insights into previously unrecognized substrate specificity determinants in AH. Two residues, Tyr(299) and Arg(307), are within hydrogen bonding distance of a carboxylate moiety of malonate. Both Tyr(299) and Arg(307) were mutated, and the resulting modified enzymes revealed >3 order of magnitude reductions in both catalytic efficiency and substrate stringency. It is proposed that Tyr(299) and Arg(307) serve to anchor and orient the substrate for attack by the catalytic nucleophile, Ser(172). The structure further suggests the presence of a unique C-terminal domain in AH. While this domain is conserved, it does not contribute to catalysis or to the structural integrity of the core domain, suggesting that it may play a role in mediating transient and specific interactions with the urea carboxylase component of urea amidolyase. Analysis of the AH active site architecture offers new insights into common determinants of catalysis and specificity among divergent members of the amidase signature family.


    Organizational Affiliation

    Department of Biological Sciences, Marquette University, Milwaukee, WI 53201, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Allophanate hydrolase
A, B
621Granulibacter bethesdensis (strain ATCC BAA-1260 / CGDNIH1)EC: 3.5.1.54
Find proteins for Q0BRB0 (Granulibacter bethesdensis (strain ATCC BAA-1260 / CGDNIH1))
Go to UniProtKB:  Q0BRB0
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.8 Å
  • R-Value Free: 0.307 
  • R-Value Work: 0.256 
  • Space Group: P 61
Unit Cell:
Length (Å)Angle (°)
a = 78.094α = 90.00
b = 78.094β = 90.00
c = 397.543γ = 120.00
Software Package:
Software NamePurpose
HKL-2000data scaling
PHENIXphasing
MC-2data collection
PHENIXrefinement
HKL-2000data reduction
PHENIXmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2013-01-30
    Type: Initial release
  • Version 1.1: 2013-02-20
    Type: Database references
  • Version 1.2: 2017-11-15
    Type: Advisory, Refinement description