4D9C

PMP bound form of Salmonella typhimurium D-Cysteine desulfhydrase obtained after co-crystallization with L-cycloserine


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.97 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.178 

Starting Model: experimental
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Ligand Structure Quality Assessment 


This is version 1.1 of the entry. See complete history


Literature

Structural and Mutational Studies on Substrate Specificity and Catalysis of Salmonella typhimurium D-Cysteine Desulfhydrase.

Bharath, S.R.Bisht, S.Harijan, R.K.Savithri, H.S.Murthy, M.R.N.

(2012) PLoS One 7: e36267-e36267

  • DOI: https://doi.org/10.1371/journal.pone.0036267
  • Primary Citation of Related Structures:  
    4D8T, 4D8U, 4D8W, 4D92, 4D96, 4D97, 4D99, 4D9B, 4D9C, 4D9E, 4D9F

  • PubMed Abstract: 

    Salmonella typhimurium DCyD (StDCyD) is a fold type II pyridoxal 5' phosphate (PLP)-dependent enzyme that catalyzes the degradation of D-Cys to H(2)S and pyruvate. It also efficiently degrades β-chloro-D-alanine (βCDA). D-Ser is a poor substrate while the enzyme is inactive with respect to L-Ser and 1-amino-1-carboxy cyclopropane (ACC). Here, we report the X-ray crystal structures of StDCyD and of crystals obtained in the presence of D-Cys, βCDA, ACC, D-Ser, L-Ser, D-cycloserine (DCS) and L-cycloserine (LCS) at resolutions ranging from 1.7 to 2.6 Å. The polypeptide fold of StDCyD consisting of a small domain (residues 48-161) and a large domain (residues 1-47 and 162-328) resembles other fold type II PLP dependent enzymes. The structures obtained in the presence of D-Cys and βCDA show the product, pyruvate, bound at a site 4.0-6.0 Å away from the active site. ACC forms an external aldimine complex while D- and L-Ser bind non-covalently suggesting that the reaction with these ligands is arrested at Cα proton abstraction and transimination steps, respectively. In the active site of StDCyD cocrystallized with DCS or LCS, electron density for a pyridoxamine phosphate (PMP) was observed. Crystals soaked in cocktail containing these ligands show density for PLP-cycloserine. Spectroscopic observations also suggest formation of PMP by the hydrolysis of cycloserines. Mutational studies suggest that Ser78 and Gln77 are key determinants of enzyme specificity and the phenolate of Tyr287 is responsible for Cα proton abstraction from D-Cys. Based on these studies, a probable mechanism for the degradation of D-Cys by StDCyD is proposed.


  • Organizational Affiliation

    Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
D-Cysteine desulfhydrase
A, B, C, D
342Salmonella enterica subsp. enterica serovar TyphimuriumMutation(s): 0 
Gene Names: dcyDSTM1953
EC: 4.4.1.15
UniProt
Find proteins for Q8ZNT7 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Explore Q8ZNT7 
Go to UniProtKB:  Q8ZNT7
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8ZNT7
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.97 Å
  • R-Value Free: 0.231 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.178 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 66.512α = 90
b = 165.497β = 118.89
c = 68.638γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
PHASERphasing
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-05-30
    Type: Initial release
  • Version 1.1: 2023-11-08
    Changes: Data collection, Database references, Derived calculations, Refinement description