4I8A

Alanine-glyoxylate aminotransferase variant S187F


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.251 
  • R-Value Observed: 0.253 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Crystal structure of the S187F variant of human liver alanine: Aminotransferase associated with primary hyperoxaluria type I and its functional implications.

Oppici, E.Fodor, K.Paiardini, A.Williams, C.Voltattorni, C.B.Wilmanns, M.Cellini, B.

(2013) Proteins 81: 1457-1465

  • DOI: 10.1002/prot.24300
  • Primary Citation of Related Structures:  
    4I8A

  • PubMed Abstract: 
  • The substitution of Ser187, a residue located far from the active site of human liver peroxisomal alanine:glyoxylate aminotransferase (AGT), by Phe gives rise to a variant associated with primary hyperoxaluria type I. Unexpectedly, previous studies revealed that the recombinant form of S187F exhibits a remarkable loss of catalytic activity, an increased pyridoxal 5'-phosphate (PLP) binding affinity and a different coenzyme binding mode compared with normal AGT ...

    The substitution of Ser187, a residue located far from the active site of human liver peroxisomal alanine:glyoxylate aminotransferase (AGT), by Phe gives rise to a variant associated with primary hyperoxaluria type I. Unexpectedly, previous studies revealed that the recombinant form of S187F exhibits a remarkable loss of catalytic activity, an increased pyridoxal 5'-phosphate (PLP) binding affinity and a different coenzyme binding mode compared with normal AGT. To shed light on the structural elements responsible for these defects, we solved the crystal structure of the variant to a resolution of 2.9 Å. Although the overall conformation of the variant is similar to that of normal AGT, we noticed: (i) a displacement of the PLP-binding Lys209 and Val185, located on the re and si side of PLP, respectively, and (ii) slight conformational changes of other active site residues, in particular Trp108, the base stacking residue with the pyridine cofactor moiety. This active site perturbation results in a mispositioning of the AGT-pyridoxamine 5'-phosphate (PMP) complex and of the external aldimine, as predicted by molecular modeling studies. Taken together, both predicted and observed movements caused by the S187F mutation are consistent with the following functional properties of the variant: (i) a 300- to 500-fold decrease in both the rate constant of L-alanine half-transamination and the kcat of the overall transamination, (ii) a different PMP binding mode and affinity, and (iii) a different microenvironment of the external aldimine. Proposals for the treatment of patients bearing S187F mutation are discussed on the basis of these results.


    Organizational Affiliation

    Department of Life Sciences and Reproduction, Section of Biological Chemistry, University of Verona, Verona, Italy.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Serine-pyruvate aminotransferaseA, B, C, D394Homo sapiensMutation(s): 1 
Gene Names: AGXTAGT1SPAT
EC: 2.6.1.51 (PDB Primary Data), 2.6.1.44 (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for P21549 (Homo sapiens)
Explore P21549 
Go to UniProtKB:  P21549
PHAROS:  P21549
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.90 Å
  • R-Value Free: 0.278 
  • R-Value Work: 0.251 
  • R-Value Observed: 0.253 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 78.892α = 90
b = 101.564β = 90.64
c = 116.749γ = 90
Software Package:
Software NamePurpose
DNAdata collection
PHASERphasing
REFMACrefinement
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2013-05-01
    Type: Initial release
  • Version 1.1: 2013-08-07
    Changes: Database references