Premium
Broad antibiotic resistance profile of the subclass B3 metallo‐β‐lactamase GOB‐1, a di‐zinc enzyme
Author(s) -
Horsfall Louise E.,
Izougarhane Youssef,
Lassaux Patricia,
Selevsek Nathalie,
Liénard Benoit M. R.,
Poirel Laurent,
Kupper Michael B.,
Hoffmann Kurt M.,
Frère JeanMarie,
Galleni Moreno,
Bebrone Carine
Publication year - 2011
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2011.08046.x
Subject(s) - zinc , enzyme , mutant , residue (chemistry) , escherichia coli , chemistry , subclass , active site , wild type , biochemistry , binding site , stereochemistry , biology , gene , antibody , genetics , organic chemistry
The metallo‐β‐lactamase (MBL) GOB‐1 was expressed via a T7 expression system in Escherichia coli BL21(DE3). The MBL was purified to homogeneity and shown to exhibit a broad substrate profile, hydrolyzing all the tested β‐lactam compounds efficiently. The GOB enzymes are unique among MBLs due to the presence of a glutamine residue at position 116, a zinc‐binding residue in all known class B1 and B3 MBL structures. Here we produced and studied the Q116A, Q116N and Q116H mutants. The substrate profiles were similar for each mutant, but with significantly reduced activity compared with that of the wild‐type. In contrast to the Q116H enzyme, which bound two zinc ions just like the wild‐type, only one zinc ion is present in Q116A and Q116N. These results suggest that the Q116 residue plays a role in the binding of the zinc ion in the QHH site.