2ZTJ

Crystal structure of homocitrate synthase from Thermus thermophilus complexed with alpha-ketoglutarate


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.200 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Mechanism of substrate recognition and insight into feedback inhibition of homocitrate synthase from Thermus thermophilus

Okada, T.Tomita, T.Wulandari, A.P.Kuzuyama, T.Nishiyama, M.

(2010) J Biol Chem 285: 4195-4205

  • DOI: 10.1074/jbc.M109.086330
  • Primary Citation of Related Structures:  
    2ZTJ, 2ZTK, 3A9I, 2ZYF

  • PubMed Abstract: 
  • Homocitrate synthase (HCS) catalyzes aldol-type condensation of acetyl coenzyme A (acetyl-CoA) and alpha-ketoglutarate (alpha-KG) to synthesize homocitrate (HC), which is the first and committed step in the lysine biosynthetic pathway through alpha-aminoadipate ...

    Homocitrate synthase (HCS) catalyzes aldol-type condensation of acetyl coenzyme A (acetyl-CoA) and alpha-ketoglutarate (alpha-KG) to synthesize homocitrate (HC), which is the first and committed step in the lysine biosynthetic pathway through alpha-aminoadipate. As known in most enzymes catalyzing the first reactions in amino acid biosynthetic pathways, HCS is regulated via feedback inhibition by the end product, lysine. Here, we determined the crystal structures of HCS from Thermus thermophilus complexed with alpha-KG, HC, or lysine. In the HC complex, the C1-carboxyl group of HC, which is derived from acetyl-CoA, is hydrogen-bonded with His-292* from another subunit (indicated by the asterisk), indicating direct involvement of this residue in the catalytic mechanism of HCS. The crystal structure of HCS complexed with lysine showed that lysine is bound to the active site with rearrangement of amino acid residues in the substrate-binding site, which accounts for the competitive inhibition by lysine with alpha-KG. Comparison between the structures suggests that His-72, which is conserved in lysine-sensitive HCSs and binds the C5-carboxyl group of alpha-KG, serves as a switch for the conformational change. Replacement of His-72 by leucine made HCS resistant to lysine inhibition, demonstrating the regulatory role of this conserved residue.


    Organizational Affiliation

    Biotechnology Research Center, University of Tokyo, Tokyo 113-8657, Japan.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Homocitrate synthaseA382Thermus thermophilus HB27Mutation(s): 0 
Gene Names: hcslys20TT_C1550
EC: 2.3.3.14
Find proteins for O87198 (Thermus thermophilus (strain HB27 / ATCC BAA-163 / DSM 7039))
Explore O87198 
Go to UniProtKB:  O87198
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
AKG
Query on AKG

Download Ideal Coordinates CCD File 
B [auth A]2-OXOGLUTARIC ACID
C5 H6 O5
KPGXRSRHYNQIFN-UHFFFAOYSA-N
 Ligand Interaction
CU
Query on CU

Download Ideal Coordinates CCD File 
C [auth A]COPPER (II) ION
Cu
JPVYNHNXODAKFH-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.224 
  • R-Value Work: 0.199 
  • R-Value Observed: 0.200 
  • Space Group: P 63 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 135.645α = 90
b = 135.645β = 90
c = 127.102γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-10-13
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Non-polymer description, Version format compliance
  • Version 1.2: 2012-01-25
    Changes: Advisory, Database references, Experimental preparation