5OG0

Crystal structure of human Alanine:Glyoxylate Aminotransferase major allele (AGT-Ma) at 2.5 Angstrom; internal aldimine with PLP in the active site


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.294 
  • R-Value Work: 0.255 

wwPDB Validation 3D Report Full Report


This is version 1.0 of the entry. See complete history

Literature

Radiation damage at the active site of human alanine:glyoxylate aminotransferase reveals that the cofactor position is finely tuned during catalysis.

Giardina, G.Paiardini, A.Montioli, R.Cellini, B.Voltattorni, C.B.Cutruzzola, F.

(2017) Sci Rep 7: 11704-11704

  • DOI: 10.1038/s41598-017-11948-w
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The alanine:glyoxylate aminotransferase (AGT), a hepatocyte-specific pyridoxal-5'-phosphate (PLP) dependent enzyme, transaminates L-alanine and glyoxylate to glycine and pyruvate, thus detoxifying glyoxylate and preventing pathological oxalate precip ...

    The alanine:glyoxylate aminotransferase (AGT), a hepatocyte-specific pyridoxal-5'-phosphate (PLP) dependent enzyme, transaminates L-alanine and glyoxylate to glycine and pyruvate, thus detoxifying glyoxylate and preventing pathological oxalate precipitation in tissues. In the widely accepted catalytic mechanism of the aminotransferase family, the lysine binding to PLP acts as a catalyst in the stepwise 1,3-proton transfer, interconverting the external aldimine to ketimine. This step requires protonation by a conserved aspartate of the pyridine nitrogen of PLP to enhance its ability to stabilize the carbanionic intermediate. The aspartate residue is also responsible for a significant geometrical distortion of the internal aldimine, crucial for catalysis. We present the structure of human AGT in which complete X-ray photoreduction of the Schiff base has occurred. This result, together with two crystal structures of the conserved aspartate pathogenic variant (D183N) and the molecular modeling of the transaldimination step, led us to propose that an interplay of opposite forces, which we named spring mechanism, finely tunes PLP geometry during catalysis and is essential to move the external aldimine in the correct position in order for the 1,3-proton transfer to occur.


    Organizational Affiliation

    Department of Biochemical Sciences "A. Rossi Fanelli", Sapienza University of Rome, Rome, Italy. giorgio.giardina@uniroma1.it.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Serine--pyruvate aminotransferase
A
392Homo sapiensMutation(s): 0 
Gene Names: AGXT (AGT1, SPAT)
EC: 2.6.1.51
Find proteins for P21549 (Homo sapiens)
Go to Gene View: AGXT
Go to UniProtKB:  P21549
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLP
Query on PLP

Download SDF File 
Download CCD File 
A
PYRIDOXAL-5'-PHOSPHATE
VITAMIN B6 Phosphate
C8 H10 N O6 P
NGVDGCNFYWLIFO-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.294 
  • R-Value Work: 0.255 
  • Space Group: P 41 21 2
Unit Cell:
Length (Å)Angle (°)
a = 90.673α = 90.00
b = 90.673β = 90.00
c = 141.197γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
Aimlessdata scaling
MOLREPphasing
XDSdata reduction
PDB_EXTRACTdata extraction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2017-09-27
    Type: Initial release