1AJS

REFINEMENT AND COMPARISON OF THE CRYSTAL STRUCTURES OF PIG CYTOSOLIC ASPARTATE AMINOTRANSFERASE AND ITS COMPLEX WITH 2-METHYLASPARTATE

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Observed: 0.173 

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This is version 1.2 of the entry. See complete history. 


Literature

Refinement and comparisons of the crystal structures of pig cytosolic aspartate aminotransferase and its complex with 2-methylaspartate.

Rhee, S., Silva, M.M., Hyde, C.C., Rogers, P.H., Metzler, C.M., Metzler, D.E., Arnone, A.

(1997) J Biol Chem 272: 17293-17302

  • Primary Citation of Related Structures:  
    1AJS, 1AJR

  • PubMed Abstract: 

    • Two high resolution crystal structures of cytosolic aspartate aminotransferase from pig heart provide additional insights into the stereochemical mechanism for ligand-induced conformational changes in this enzyme. Structures of the homodimeric native ...

    Two high resolution crystal structures of cytosolic aspartate aminotransferase from pig heart provide additional insights into the stereochemical mechanism for ligand-induced conformational changes in this enzyme. Structures of the homodimeric native structure and its complex with the substrate analog 2-methylaspartate have been refined, respectively, with 1.74-A x-ray diffraction data to an R value of 0.170, and with 1.6-A data to an R value of 0.173. In the presence of 2-methylaspartate, one of the subunits (subunit 1) shows a ligand-induced conformational change that involves a large movement of the small domain (residues 12-49 and 327-412) to produce a "closed" conformation. No such transition is observed in the other subunit (subunit 2), because crystal lattice contacts lock it in an "open" conformation like that adopted by subunit 1 in the absence of substrate. By comparing the open and closed forms of cAspAT, we propose a stereochemical mechanism for the open-to-closed transition that involves the electrostatic neutralization of two active site arginine residues by the negative charges of the incoming substrate, a large change in the backbone (phi,psi) conformational angles of two key glycine residues, and the entropy-driven burial of a stretch of hydrophobic residues on the N-terminal helix. The calculated free energy for the burial of this "hydrophobic plug" appears to be sufficient to serve as the driving force for domain closure.

    Related Citations: 
    • Pig Cytosolic Aspartate Aminotransferase
      Arnone, A., Rogers, P.H., Hyde, C.C., Briley, P.D., Metzler, C.M., Metzler, D.E.
      (1985) Transaminases --: 138
    Organizational Affiliation: 

    Department of Biochemistry, University of Iowa, Iowa City, Iowa 52242, USA.



Macromolecules
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
ASPARTATE AMINOTRANSFERASEA412Sus scrofaMutation(s): 0 
Gene Names: GOT1
EC: 2.6.1.1 (PDB Primary Data), 2.6.1.3 (UniProt)
Find proteins for P00503 (Sus scrofa)
Explore P00503 
Go to UniProtKB:  P00503
Protein Feature View
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  • Reference Sequence
Find similar proteins by: 
(by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
ASPARTATE AMINOTRANSFERASEB412Sus scrofaMutation(s): 1 
Gene Names: GOT1
EC: 2.6.1.1 (PDB Primary Data), 2.6.1.3 (UniProt)
Find proteins for P00503 (Sus scrofa)
Explore P00503 
Go to UniProtKB:  P00503
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PLA
Query on PLA
Download Ideal Coordinates CCD File 
A
2-[(3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-YLMETHYL)-AMINO]-2-METHYL-SUCCINIC ACID
C13 H19 N2 O9 P
ZFKRUCNEKPIDBK-ZDUSSCGKSA-N		 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
LLP
Query on LLP		BL-PEPTIDE LINKINGC14 H22 N3 O7 PLYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.60 Å
  • R-Value Observed: 0.173 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 125α = 90
b = 130.8β = 90
c = 55.8γ = 90
Software Package:
Software NamePurpose
SEEmodel building
PROLSQrefinement
UCSDdata reduction
FROMdata scaling

Structure Validation

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View more in-depth experimental data

Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-08-20
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance