Department of Chemical Engineering, Iowa State University, Ames 50011.
Protein Eng 7: 749-60 (1994)
Abstract
The model of the catalytic domain of Aspergillus awamori var. X100
glucoamylase was related to 14 other glucoamylase protein sequences
belonging to five subfamilies. Structural features of the different
sequences were revealed by multisequence alignment following hydrophobic
cluster analysis. The alignment agreed with the hydrophobic
microdomains, normally conserved throughout evolution, evaluated from
the 3-D model. Saccharomyces and Clostridium glucoamylases lack the
alpha-helix exterior to the catalytic domain. A different catalytic base
was found in the Saccharomyces glucoamylase subfamily. The starch
binding domain of fungal glucoamylases has identical structural features
and substrate interacting residues as the C-terminal domain of models
of Bacillus circulans cyclodextrin glucosyltransferases. Three putative
N-glycosylation sites were found in the same turns in glucoamylases of
different subfamilies. O-Glycosylation is present at different levels in
the catalytic domain and in the linker between the catalytic and starch
binding domains.
Mesh Headings
Unique Identifier: 95023838
Chemical Identifiers (Names)