Comparison of Amino Acid Sequences of Three Glucoamylases and Their Structure-Function Relationships

Abstract

Amino acid sequences of three glucoamylases from Rhizopus, Aspergillus, and Saccharomyces were compared and the overall homology was from 25 to 36%. A greater homology was observed in four distinct regions suggesting that they may be functionally constrained amino acid sequences. Rhizopus and Aspergillus glucoamylases were more closely related among the three. The structure-function relationships of glucoamylase are discussed based on sequence comparison, probable secondary structures, and the hydropathy profiles.