Motion of the zinc ions in catalysis by a dizinc metallo-beta-lactamase. J Am Chem Soc 2009 Aug 26;131(33):11642-3
Date
08/06/2009Pubmed ID
19653676Pubmed Central ID
PMC3571662DOI
10.1021/ja902534bScopus ID
2-s2.0-69049101137 (requires institutional sign-in at Scopus site) 32 CitationsAbstract
We report rapid-freeze-quench X-ray absorption spectroscopy of a dizinc metallo-beta-lactamase (MbetaL) reaction intermediate. The Zn(II) ions in the dinuclear active site of the S. maltophilia Class B3 MbetaL move away from each other, by approximately 0.3 A after 10 ms of reaction with nitrocefin, from 3.4 to 3.7 A. Together with our previous characterization of the resting enzyme and its nitrocefin product complex, where the Zn(II) ion separation relaxes to 3.6 A, these data indicate a scissoring motion of the active site that accompanies the ring-opening step. The average Zn(II) coordination number of 4.5 in the resting enzyme appears to be maintained throughout the reaction with nitrocefin. This is the first direct structural information available on early stage dizinc metallo-beta-lactamase catalysis.
Author List
Breece RM, Hu Z, Bennett B, Crowder MW, Tierney DLAuthor
Brian Bennett D.Phil. Professor and Chair in the Physics department at Marquette UniversityMESH terms used to index this publication - Major topics in bold
AbsorptionBiocatalysis
Crystallography, X-Ray
Fourier Analysis
Motion
Spectrum Analysis
Stenotrophomonas maltophilia
Zinc
beta-Lactamases
