Biological Assembly 1  

 3D View: Structure | Ligand Interaction

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

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

Macromolecule Content

• Total Structure Weight: 84.95 kDa 
• Atom Count: 6272 
• Residue Count: 764 
• Unique protein chains: 1

1B5P

THERMUS THERMOPHILUS ASPARTATE AMINOTRANSFERASE DOUBLE MUTANT 1

• DOI: 10.2210/pdb1B5P/pdb

• Classification: TRANSFERASE
• Organism(s): Thermus thermophilus HB8
• Expression System: Escherichia coli
• Mutation(s): Yes 


• Deposited: 1999-01-07 Released: 2003-09-02 
• Deposition Author(s): Ura, H., Nakai, T., Kawaguchi, S.I., Miyahara, I., Hirotsu, K., Kuramitsu, S.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.239 
• R-Value Work: 0.193 
• R-Value Observed: 0.193 

Literature

Substrate recognition mechanism of thermophilic dual-substrate enzyme

Ura, H., Nakai, T., Kawaguchi, S.I., Miyahara, I., Hirotsu, K., Kuramitsu, S.

(2001) J Biochem 130: 89-98

• PubMed: 11432784 
• DOI: 10.1093/oxfordjournals.jbchem.a002966
• Primary Citation of Related Structures:  
  1GCK, 1GC4, 1GC3, 5BJ4, 5BJ3, 1B5P, 1B5O


• PubMed Abstract: 
  

Aspartate aminotransferase from an extremely thermophilic bacterium, Thermus thermophilus HB8 (ttAspAT), has been believed to be specific for an acidic substrate. However, stepwise introduction of mutations in the active-site residues finally changed its substrate specificity to that of a dual-substrate enzyme. The final mutant, [S15D, T17V, K109S, S292R] ttAspAT, is active toward both acidic and hydrophobic substrates. During the course of stepwise mutation, the activities toward acidic and hydrophobic substrates changed independently. The introduction of a mobile Arg292* residue into ttAspAT was the key step in the change to a "dual-substrate" enzyme. The substrate recognition mechanism of this thermostable "dual-substrate" enzyme was confirmed by X-ray crystallography. This work together with previous studies on various enzymes suggest that this unique "dual-substrate recognition" mechanism is a feature of not only aminotransferases but also other enzymes.

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Organizational Affiliation: 

Department of Biology, Graduate School of Science, Osaka University, Machikaneyama-cho, Toyonaka, Osaka 560-0043, Japan.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PROTEIN (ASPARTATE AMINOTRANSFERASE)	A, B	385	Thermus thermophilus HB8	Mutation(s): 2  Gene Names: aspC, TTHA0046 EC: 2.6.1.1 (PDB Primary Data), 2.6.1.78 (UniProt)
Find proteins for Q56232 (Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)) Explore Q56232  Go to UniProtKB:  Q56232

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
PLP	A, B	PYRIDOXAL-5'-PHOSPHATE C8 H10 N O6 P NGVDGCNFYWLIFO-UHFFFAOYSA-N
PO4	A, B	PHOSPHATE ION O4 P NBIIXXVUZAFLBC-UHFFFAOYSA-K

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.80 Å
• R-Value Free: 0.239 
• R-Value Work: 0.193 
• R-Value Observed: 0.193 
• Space Group: P 2₁ 2₁ 2₁

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 61.49	α = 90
b = 113.62	β = 90
c = 124.4	γ = 90

Software Package:

Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
X-PLOR	model building
X-PLOR	refinement
X-PLOR	phasing

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 1999-01-07 
• Released Date: 2003-09-02 
Deposition Author(s): Ura, H., Nakai, T., Kawaguchi, S.I., Miyahara, I., Hirotsu, K., Kuramitsu, S.

Revision History 

• Version 1.0: 2003-09-02
  Type: Initial release
  
• Version 1.1: 2008-04-27
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Source and taxonomy, Version format compliance