1CP9

CRYSTAL STRUCTURE OF PENICILLIN G ACYLASE FROM THE BRO1 MUTANT STRAIN OF PROVIDENCIA RETTGERI


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.165 
  • R-Value Work: 0.154 
  • R-Value Observed: 0.154 

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This is version 1.3 of the entry. See complete history


Literature

Crystal structure of penicillin G acylase from the Bro1 mutant strain of Providencia rettgeri.

McDonough, M.A.Klei, H.E.Kelly, J.A.

(1999) Protein Sci 8: 1971-1981

  • DOI: 10.1110/ps.8.10.1971
  • Primary Citation of Related Structures:  
    1CP9

  • PubMed Abstract: 
  • Penicillin G acylase is an important enzyme in the commercial production of semisynthetic penicillins used to combat bacterial infections. Mutant strains of Providencia rettgeri were generated from wild-type cultures subjected to nutritional selective pressure ...

    Penicillin G acylase is an important enzyme in the commercial production of semisynthetic penicillins used to combat bacterial infections. Mutant strains of Providencia rettgeri were generated from wild-type cultures subjected to nutritional selective pressure. One such mutant, Bro1, was able to use 6-bromohexanamide as its sole nitrogen source. Penicillin acylase from the Bro1 strain exhibited an altered substrate specificity consistent with the ability of the mutant to process 6-bromohexanamide. The X-ray structure determination of this enzyme was undertaken to understand its altered specificity and to help in the design of site-directed mutants with desired specificities. In this paper, the structure of the Bro1 penicillin G acylase has been solved at 2.5 A resolution by molecular replacement. The R-factor after refinement is 0.154 and R-free is 0.165. Of the 758 residues in the Bro1 penicillin acylase heterodimer (alpha-subunit, 205; beta-subunit, 553), all but the eight C-terminal residues of the alpha-subunit have been modeled based on a partial Bro1 sequence and the complete wild-type P. rettgeri sequence. A tightly bound calcium ion coordinated by one residue from the alpha-subunit and five residues from the beta-subunit has been identified. This enzyme belongs to the superfamily of Ntn hydrolases and uses Ogamma of Ser beta1 as the characteristic N-terminal nucleophile. A mutation of the wild-type Met alpha140 to Leu in the Bro1 acylase hydrophobic specificity pocket is evident from the electron density and is consistent with the observed specificity change for Bro1 acylase. The electron density for the N-terminal Gln of the alpha-subunit is best modeled by the cyclized pyroglutamate form. Examination of aligned penicillin acylase and cephalosporin acylase primary sequences, in conjunction with the P. rettgeri and Escherichia coli penicillin acylase crystal structures, suggests several mutations that could potentially allow penicillin acylase to accept charged beta-lactam R-groups and to function as a cephalosporin acylase and thus be used in the manufacture of semi-synthetic cephalosporins.


    Organizational Affiliation

    Department of Molecular and Cell Biology, University of Connecticut, Storrs 06269-3125, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Penicillin G amidaseA205Providencia rettgeriMutation(s): 1 
UniProt
Find proteins for Q7WZI9 (Providencia rettgeri)
Explore Q7WZI9 
Go to UniProtKB:  Q7WZI9
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Penicillin G amidaseB553Providencia rettgeriMutation(s): 0 
UniProt
Find proteins for Q7WZI9 (Providencia rettgeri)
Explore Q7WZI9 
Go to UniProtKB:  Q7WZI9
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
PCA
Query on PCA
AL-PEPTIDE LINKINGC5 H7 N O3GLN
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.50 Å
  • R-Value Free: 0.165 
  • R-Value Work: 0.154 
  • R-Value Observed: 0.154 
  • Space Group: P 61 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 140.645α = 90
b = 140.645β = 90
c = 200.189γ = 120
Software Package:
Software NamePurpose
X-PLORrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1999-06-24
    Type: Initial release
  • Version 1.1: 2008-04-26
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2017-06-28
    Changes: Advisory, Database references, Refinement description, Source and taxonomy, Structure summary