2AIO

Metallo beta lactamase L1 from Stenotrophomonas maltophilia complexed with hydrolyzed moxalactam


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.173 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Antibiotic Recognition by Binuclear Metallo-beta-Lactamases Revealed by X-ray Crystallography

Spencer, J.Read, J.Sessions, R.B.Howell, S.Blackburn, G.M.Gamblin, S.J.

(2005) J Am Chem Soc 127: 14439-14444

  • DOI: 10.1021/ja0536062
  • Primary Citation of Related Structures:  
    2AIO

  • PubMed Abstract: 
  • Metallo-beta-lactamases are zinc-dependent enzymes responsible for resistance to beta-lactam antibiotics in a variety of host bacteria, usually Gram-negative species that act as opportunist pathogens. They hydrolyze all classes of beta-lactam antibio ...

    Metallo-beta-lactamases are zinc-dependent enzymes responsible for resistance to beta-lactam antibiotics in a variety of host bacteria, usually Gram-negative species that act as opportunist pathogens. They hydrolyze all classes of beta-lactam antibiotics, including carbapenems, and escape the action of available beta-lactamase inhibitors. Efforts to develop effective inhibitors have been hampered by the lack of structural information regarding how these enzymes recognize and turn over beta-lactam substrates. We report here the crystal structure of the Stenotrophomonas maltophilia L1 enzyme in complex with the hydrolysis product of the 7alpha-methoxyoxacephem, moxalactam. The on-enzyme complex is a 3'-exo-methylene species generated by elimination of the 1-methyltetrazolyl-5-thiolate anion from the 3'-methyl group. Moxalactam binding to L1 involves direct interaction of the two active site zinc ions with the beta-lactam amide and C4 carboxylate, groups that are common to all beta-lactam substrates. The 7beta-[(4-hydroxyphenyl)malonyl]-amino substituent makes limited hydrophobic and hydrogen bonding contacts with the active site groove. The mode of binding provides strong evidence that a water molecule situated between the two metal ions is the most likely nucleophile in the hydrolytic reaction. These data suggest a reaction mechanism for metallo-beta-lactamases in which both metal ions contribute to catalysis by activating the bridging water/hydroxide nucleophile, polarizing the substrate amide bond for attack and stabilizing anionic nitrogen intermediates. The structure illustrates how a binuclear zinc site confers upon metallo-beta-lactamases the ability both to recognize and efficiently hydrolyze a wide variety of beta-lactam substrates.


    Organizational Affiliation

    Departments of Cellular and Molecular Medicine and Biochemistry, University of Bristol School of Medical Sciences, University Walk, Bristol BS8 1TD, United Kingdom.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Metallo-beta-lactamase L1A269Stenotrophomonas maltophiliaMutation(s): 0 
Gene Names: blaL1
EC: 3.5.2.6
Find proteins for P52700 (Stenotrophomonas maltophilia)
Explore P52700 
Go to UniProtKB:  P52700
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MX1
Query on MX1

Download CCD File 
A
(2R)-2-((R)-CARBOXY{[CARBOXY(4-HYDROXYPHENYL)ACETYL]AMINO}METHOXYMETHYL)-5-METHYLENE-5,6-DIHYDRO-2H-1,3-OXAZINE-4-CARBO XYLIC ACID
C18 H18 N2 O10
ZTOQXKUYWZBJLG-XNAIMREJSA-N
 Ligand Interaction
SO4
Query on SO4

Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
ZN
Query on ZN

Download CCD File 
A
ZINC ION
Zn
PTFCDOFLOPIGGS-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.70 Å
  • R-Value Free: 0.200 
  • R-Value Work: 0.171 
  • R-Value Observed: 0.173 
  • Space Group: P 64 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 105.024α = 90
b = 105.024β = 90
c = 98.23γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
DENZOdata reduction
SCALEPACKdata scaling
AMoREphasing

Structure Validation

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Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-10-11
    Type: Initial release
  • Version 1.1: 2007-10-16
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Derived calculations, Version format compliance