MOLECULAR HETEROGENEITY OF THE L-1 METALLO-BETA-LACTAMASE FAMILY FROMSTENOTROPHOMONAS-MALTOPHILIA

We have determined the nucleotide sequence of the blaS gene encoding t he carbapenem-hydrolyzing L-l beta-lactamase from Stenotrophomonas mal tophilia GN12873. Analysis of the DNA and deduced amino acid sequences identified a product of 290 amino acids. Comparisons of the L-l amino acid sequence with those of other zinc beta-lactamases showed 88.6% i dentify with the L-1 enzyme from S. maltophilia IID1275 and less than 20% identity with other class B metalloenzymes.