2Q3D

2.2 A Resolution Crystal Structure of O-Acetylserine Sulfhydrylase (OASS) From MYCOBACTERIUM TUBERCULOSIS in Complex with the Reaction Intermediate ALPHA-AMINOACRYLATE


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural Insights into Catalysis and Inhibition of O-Acetylserine Sulfhydrylase from Mycobacterium tuberculosis: CRYSTAL STRUCTURES OF THE ENZYME {alpha}-AMINOACRYLATE INTERMEDIATE AND AN ENZYME-INHIBITOR COMPLEX.

Schnell, R.Oehlmann, W.Singh, M.Schneider, G.

(2007) J Biol Chem 282: 23473-23481

  • DOI: 10.1074/jbc.M703518200
  • Primary Citation of Related Structures:  
    2Q3D, 2Q3C, 2Q3B

  • PubMed Abstract: 
  • Cysteine biosynthetic genes are up-regulated in the persistent phase of Mycobacterium tuberculosis, and the corresponding enzymes are therefore of interest as potential targets for novel antibacterial agents. cysK1 is one of these genes and has been ...

    Cysteine biosynthetic genes are up-regulated in the persistent phase of Mycobacterium tuberculosis, and the corresponding enzymes are therefore of interest as potential targets for novel antibacterial agents. cysK1 is one of these genes and has been annotated as coding for an O-acetylserine sulfhydrylase. Recombinant CysK1 is a pyridoxal phosphate (PLP)-dependent enzyme that catalyzes the conversion of O-acetylserine to cysteine. The crystal structure of the enzyme was determined to 1.8A resolution. CysK1 belongs to the family of fold type II PLP enzymes and is similar in structure to other O-acetylserine sulfhydrylases. We were able to trap the alpha-aminoacrylate reaction intermediate and determine its structure by cryocrystallography. Formation of the aminoacrylate complex is accompanied by a domain rotation resulting in active site closure. The aminoacrylate moiety is bound in the active site via the covalent linkage to the PLP cofactor and by hydrogen bonds of its carboxyl group to several enzyme residues. The catalytic lysine residue is positioned such that it can protonate the Calpha-carbon atom of the aminoacrylate only from the si-face, resulting in the formation of L-cysteine. CysK1 is competitively inhibited by a four-residue peptide derived from the C-terminal of serine acetyl transferase. The crystallographic analysis reveals that the peptide binds to the enzyme active site, suggesting that CysK1 forms an bi-enzyme complex with serine acetyl transferase, in a similar manner to other bacterial and plant O-acetylserine sulfhydrylases. The structure of the enzyme-peptide complex provides a framework for the design of strong binding inhibitors.


    Organizational Affiliation

    Department of Medical Biochemistry and Biophysics, Karolinska Institutet, S-171 77 Stockholm, Sweden.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Cysteine synthase AA313Mycobacterium tuberculosisMutation(s): 0 
Gene Names: cysK
EC: 2.5.1.47
Find proteins for P9WP55 (Mycobacterium tuberculosis (strain ATCC 25618 / H37Rv))
Explore P9WP55 
Go to UniProtKB:  P9WP55
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PDA
Query on PDA

Download CCD File 
A
2-[(3-HYDROXY-2-METHYL-5-PHOSPHONOOXYMETHYL-PYRIDIN-4-YLMETHYL)-AMINO]-PROPIONIC ACID
C11 H17 N2 O7 P
WACJCHFWJNNBPR-ZETCQYMHSA-N
 Ligand Interaction
MPD
Query on MPD

Download CCD File 
A
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.194 
  • R-Value Observed: 0.196 
  • Space Group: P 41 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 71.785α = 90
b = 71.785β = 90
c = 181.179γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MARCCD-mxCubedata collection
MOSFLMdata reduction
SCALAdata scaling
MOLREPphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-06-12
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Derived calculations, Version format compliance
  • Version 1.3: 2018-03-07
    Changes: Data collection