1AHX

ASPARTATE AMINOTRANSFERASE HEXAMUTANT

• PDB DOI: https://doi.org/10.2210/pdb1AHX/pdb

• Classification: TRANSFERASE (AMINOTRANSFERASE)
• Organism(s): Escherichia coli
• Expression System: Escherichia coli
• Mutation(s): No 


• Deposited: 1995-02-21 Released: 1995-09-15 
• Deposition Author(s): Malashkevich, V.N., Jansonius, J.N.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Observed: 0.226 

Literature

Alternating arginine-modulated substrate specificity in an engineered tyrosine aminotransferase.

Malashkevich, V.N., Onuffer, J.J., Kirsch, J.F., Jansonius, J.N.

(1995) Nat Struct Biol 2: 548-553

• PubMed: 7664122 
• DOI: https://doi.org/10.1038/nsb0795-548
• Primary Citation of Related Structures:  
  1AHE, 1AHF, 1AHG, 1AHX, 1AHY


• PubMed Abstract: 
  

  Mutation of six residues of Escherichia coli aspartate aminotransferase results in substantial acquisition of the transamination properties of tyrosine amino-transferase without loss of aspartate transaminase activity. X-ray crystallographic analysis of key inhibitor complexes of the hexamutant reveals the structural basis for this substrate selectivity. It appears that tyrosine aminotransferase achieves nearly equal affinities for a wide range of amino acids by an unusual conformational switch. An active-site arginine residue either shifts its position to electrostatically interact with charged substrates or moves aside to allow access of aromatic ligands.

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Organizational Affiliation: 

Department of Structural Biology, University of Basel, Switzerland.

Biological Assembly 1  

Global Symmetry: Cyclic - C2  (Explore in 3D)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 88.07 kDa 
• Atom Count: 6,723 
• Modelled Residue Count: 792 
• Deposited Residue Count: 792 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
ASPARTATE AMINOTRANSFERASE	A, B	396	Escherichia coli	Mutation(s): 0  EC: 2.6.1.1
UniProt
Find proteins for P00509 (Escherichia coli (strain K12)) Explore P00509  Go to UniProtKB:  P00509

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PLP	C [auth A], E [auth B]	PYRIDOXAL-5'-PHOSPHATE C8 H10 N O6 P NGVDGCNFYWLIFO-UHFFFAOYSA-N
HCI	D [auth A], F [auth B]	HYDROCINNAMIC ACID C9 H10 O2 XMIIGOLPHOKFCH-UHFFFAOYSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
HCI	PDBBind:  1AHX	Kd: 1.20e+5 (nM) from 1 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.00 Å
• R-Value Observed: 0.226 
• Space Group: P 1 2₁ 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 84.98	α = 90
b = 78.69	β = 118.32
c = 89.28	γ = 90

Software Package:

Software Name	Purpose
TNT	refinement
XDS	data reduction

Structure Validation

Entry History 

Deposition Data

• Released Date: 1995-09-15 
Deposition Author(s): Malashkevich, V.N., Jansonius, J.N.

Revision History  

• Version 1.0: 1995-09-15
  Type: Initial release
  
• Version 1.1: 2008-03-03
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Non-polymer description, Version format compliance
• Version 1.3: 2022-02-16
  Changes: Database references, Derived calculations, Other