4GSZ

Crystal Structure of the Zn2+5-Human Arginase I-ABH Complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.172 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structure and function of non-native metal clusters in human arginase I.

D'Antonio, E.L.Hai, Y.Christianson, D.W.

(2012) Biochemistry 51: 8399-8409

  • DOI: 10.1021/bi301145n
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Various binuclear metal ion clusters and complexes have been reconstituted in crystalline human arginase I by removing the Mn(2+)(2) cluster of the wild-type enzyme with metal chelators and subsequently soaking the crystalline apoenzyme in buffer sol ...

    Various binuclear metal ion clusters and complexes have been reconstituted in crystalline human arginase I by removing the Mn(2+)(2) cluster of the wild-type enzyme with metal chelators and subsequently soaking the crystalline apoenzyme in buffer solutions containing NiCl(2) or ZnCl(2). X-ray crystal structures of these metal ion variants are correlated with catalytic activity measurements that reveal differences resulting from metal ion substitution. Additionally, treatment of crystalline Mn(2+)(2)-human arginase I with Zn(2+) reveals for the first time the structural basis for inhibition by Zn(2+), which forms a carboxylate-histidine-Zn(2+) triad with H141 and E277. The imidazole side chain of H141 is known to be hyper-reactive, and its chemical modification or mutagenesis is known to similarly compromise catalysis. The reactive substrate analogue 2(S)-amino-6-boronohexanoic acid (ABH) binds as a tetrahedral boronate anion to Mn(2+)(2), Co(2+)(2), Ni(2+)(2), and Zn(2+)(2) clusters in human arginase I, and it can be stabilized by a third inhibitory Zn(2+) ion coordinated by H141. Because ABH binds as an analogue of the tetrahedral intermediate and its flanking transition states in catalysis, this implies that the various metallo-substituted enzymes are capable of some level of catalysis with an actual substrate. Accordingly, we establish the following trend for turnover number (k(cat)) and catalytic efficiency (k(cat)/K(M)): Mn(2+) > Ni(2+) ≈ Co(2+) ≫ Zn(2+). Therefore, Mn(2+) is required for optimal catalysis by human arginase I.


    Organizational Affiliation

    Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Arginase-1
A, B
322Homo sapiensMutation(s): 0 
Gene Names: ARG1
EC: 3.5.3.1
Find proteins for P05089 (Homo sapiens)
Go to Gene View: ARG1
Go to UniProtKB:  P05089
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
ZN
Query on ZN

Download SDF File 
Download CCD File 
A, B
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
ABH
Query on ABH

Download SDF File 
Download CCD File 
A, B
2(S)-AMINO-6-BORONOHEXANOIC ACID
C6 H15 B N O5
BLVGFZFOWWBCCZ-YFKPBYRVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.172 
  • Space Group: P 3
Unit Cell:
Length (Å)Angle (°)
a = 91.121α = 90.00
b = 91.121β = 90.00
c = 69.772γ = 120.00
Software Package:
Software NamePurpose
CNSrefinement
CBASSdata collection
HKL-2000data scaling
HKL-2000data reduction
CNSphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-09-26
    Type: Initial release
  • Version 1.1: 2012-11-14
    Type: Database references