New families in the classification of glycosyl hydrolases based on amino acid sequence similarities

TLDR

The I.U.B. classification system groups 301 glycosyl hydrolases and related enzymes into 35 families based on amino‑acid sequence similarities. Using a 60 % increase in glycosyl hydrolase sequence data, the authors expanded the existing classification by adding members to known families and identifying ten new families. The revised scheme defines 45 families (22 polyspecific), with roughly half of all families being monospecific, and has been incorporated into the SWISS‑PROT database. Published in J.

Abstract

301 glycosyl hydrolases and related enzymes corresponding to 39 EC entries of the I.U.B. classification system have been classified into 35 families on the basis of amino-acid-sequence similarities [Henrissat (1991) Biochem. J. 280, 309-316]. Approximately half of the families were found to be monospecific (containing only one EC number), whereas the other half were found to be polyspecific (containing at least two EC numbers). A > 60% increase in sequence data for glycosyl hydrolases (181 additional enzymes or enzyme domains sequences have since become available) allowed us to update the classification not only by the addition of more members to already identified families, but also by the finding of ten new families. On the basis of a comparison of 482 sequences corresponding to 52 EC entries, 45 families, out of which 22 are polyspecific, can now be defined. This classification has been implemented in the SWISS-PROT protein sequence data bank.