Classification

The classification and nomenclature of β-lactamases has always been riddled with problems. Several schemes have been proposed for the classification of this large family of enzymes. The first proposal was to divide β-lactamases into penicillinases that hydrolyzed penicillins and cephalosporinases that attacked cephalosprins. Subsequently, the biochemical activity and substrate profiles of different enzymes formed the basis. Later, the location of genetic determinants, whether plasmid mediated, or chromosomal became incorporated into classification schemes. Isoelectric focus point and enzyme kinetic properties were basis of further classification schemes.

These schemes all had major anomalies, but advances in molecular biology and sequence analysis studies were able to resolve most of the ambiguities of the previous studies. Based on Genbank submission data, here we are grouping these enzymes in a sequence-centered manner. The gene sequences are clustered based on the three-letter designation (Eg.TEM-1) of the sequence in the Genbank flat file. We provide database search options based on country of origin, Year of reporting, the major category to which the sequence belongs (Eg. TEM, SHV, OXA etc..) and host organism. This would enable user to gather a quick information regarding the number of occurrences of a particular type of β-lactamase.

---