2QC5

Streptogramin B lyase structure


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Crystal structure and mechanism of the Staphylococcus cohnii virginiamycin B lyase (Vgb).

Lipka, M.Filipek, R.Bochtler, M.

(2008) Biochemistry 47: 4257-4265

  • DOI: 10.1021/bi7015266
  • Primary Citation of Related Structures:  
    2QC5

  • PubMed Abstract: 
  • The semisynthetic streptogramin antibiotic quinupristin/dalfopristin (trade name Synercid, Aventis Pharma) is a mixture of the A-type streptogramin dalfopristin and the B-type streptogramin quinupristin, a capped hexapeptide macrolactone. Quinupristin/dalfopristin was developed to combat multidrug resistant pathogens, but suffers from its own problems with drug resistance ...

    The semisynthetic streptogramin antibiotic quinupristin/dalfopristin (trade name Synercid, Aventis Pharma) is a mixture of the A-type streptogramin dalfopristin and the B-type streptogramin quinupristin, a capped hexapeptide macrolactone. Quinupristin/dalfopristin was developed to combat multidrug resistant pathogens, but suffers from its own problems with drug resistance. Virginiamycin B lyase (Vgb) inactivates the quinupristin component of Synercid by lactone ring opening. Remarkably, the enzyme promotes this reaction by intramolecular beta-elimination without the involvement of a water molecule. Recently, structures of S. aureus Vgb in the presence and absence of substrate were reported and used together with detailed mutagenesis data to suggest a catalytic mechanism. Here, we report an independent determination of the S. cohnii Vgb crystal structure and a biochemical characterization of the enzyme. As expected, the S. cohnii and S. aureus Vgb structures and active sites are very similar. Moreover, both enzymes catalyze quinupristin lactone ring opening with similar rate constants, albeit perhaps with different dependencies on divalent metal ions. Replacement of the conserved active site residues His228, Glu268, or His270 with alanine reduces or abolishes S. cohnii Vgb activity. Residue Lys285 in S. cohnii Vgb is spatially equivalent to the S. aureus Vgb active site residue Glu284. A glutamate but not an alanine residue can substitute for the lysine without significant loss of activity.


    Organizational Affiliation

    International Institute of Molecular and Cell Biology, Trojdena Street 4, 02-109 Warsaw, Poland.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Streptogramin B lactonaseA300Staphylococcus cohniiMutation(s): 1 
Gene Names: vgbB
EC: 4.2.99
Find proteins for O87275 (Staphylococcus cohnii)
Explore O87275 
Go to UniProtKB:  O87275
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
IOD
Query on IOD

Download CCD File 
A
IODIDE ION
I
XMBWDFGMSWQBCA-UHFFFAOYSA-M
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.80 Å
  • R-Value Free: 0.212 
  • R-Value Work: 0.179 
  • R-Value Observed: 0.180 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.465α = 90
b = 68.117β = 90
c = 73.212γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
MLPHAREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-10-14
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance