Structural analysis of glucoamylase encoded by the STA1 gene of Saccharomyces cerevisiae (var. diastaticus)

The sequence of the STA1‐encoded glucoamylase of amylolytic Saccharomyces cerevisiae (var. diastaticus) strains shows two well‐defined regions: an amino‐terminal part rich in serine and threonine residues and a carboxy‐terminal part very similar to the catalytic domain of other fungal glucoamylases....

Full description

Saved in:
Bibliographic Details
Published in:Yeast (Chichester, England) England), 2004-04, Vol.21 (5), p.379-388
Main Authors: Adam, Ana Cristina, Latorre‐García, Lorena, Polaina, Julio
Format: Article
Language:English
Subjects:
Amino Acid Sequence
amyloglucosidase
Catalytic Domain
Cloning, Molecular
DNA, Fungal - genetics
family 15 glycosyl hydrolases
flocculation
Genes, Fungal
Glucan 1,4-alpha-Glucosidase - chemistry
Glucan 1,4-alpha-Glucosidase - genetics
Glycosylation
invasins
Models, Molecular
Molecular Sequence Data
Molecular Weight
Protein Conformation
protein glycosylation
Protein Structure, Tertiary
Saccharomyces cerevisiae
Saccharomyces cerevisiae - enzymology
Saccharomyces cerevisiae - genetics
starch
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The sequence of the STA1‐encoded glucoamylase of amylolytic Saccharomyces cerevisiae (var. diastaticus) strains shows two well‐defined regions: an amino‐terminal part rich in serine and threonine residues and a carboxy‐terminal part very similar to the catalytic domain of other fungal glucoamylases. A version of the enzyme in which most of the amino‐terminal region was deleted still has glucoamylase activity, indicating that the remaining carboxy‐terminal part forms a functional catalytic domain. Homology‐based models of the two parts of the protein have been obtained. As expected, the shortened form of the enzyme is very similar to the catalytic domain of related glucoamylases of known structure. However, the amino‐terminal part yielded a structure revealing an unexpected similarity to bacterial invasins, suggesting functional connections between several yeast proteins homologous to STA1‐encoded glucoamylase and invasins. A characteristic of Saccharomyces glucoamylase in its native form is its extreme degree of glycosylation. Despite its high molecular mass (about 300 kDa), and in contrast with what occurs with other extracellular glycoproteins produced by yeast, the enzyme does not remain attached to the cell wall, being fully and efficiently secreted into the medium, even when it is produced in large amounts by overexpression of its gene. Copyright © 2004 John Wiley & Sons, Ltd.
ISSN:0749-503X
1097-0061
DOI:10.1002/yea.1102