 |
PDBsum entry 1qbd
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Glycosyl hydrolase
|
PDB id
|
|
|
|
1qbd
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Bacterial chitobiase structure provides insight into catalytic mechanism and the basis of tay-Sachs disease.
|
|
|
Authors
|
|
I.Tews,
A.Perrakis,
A.Oppenheim,
Z.Dauter,
K.S.Wilson,
C.E.Vorgias.
|
|
|
Ref.
|
|
Nat Struct Biol, 1996,
3,
638-648.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Chitin, the second most abundant polysaccharide on earth, is degraded by
chitinases and chitobiases. The structure of Serratia marcescens chitobiase has
been refined at 1.9 A resolution. The mature protein is folded into four domains
and its active site is situated at the C-terminal end of the central (beta
alpha)8-barrel. Based on the structure of the complex with the substrate
disaccharide chitobiose, we propose an acid-base reaction mechanism, in which
only one protein carboxylate acts as catalytic acid, while the nucleophile is
the polar acetamido group of the sugar in a substrate-assisted reaction. The
structural data lead to the hypothesis that the reaction proceeds with retention
of anomeric configuration. The structure allows us to model the catalytic domain
of the homologous hexosaminidases to give a structural rationale to pathogenic
mutations that underlie Tay-Sachs and Sandhoff disease.
|
|
|
Secondary reference #1
|
|
|
Title
|
|
Characterization of the human hexb gene encoding lysosomal beta-Hexosaminidase.
|
|
|
Authors
|
|
K.Neote,
B.Bapat,
A.Dumbrille-Ross,
C.Troxel,
S.M.Schuster,
D.J.Mahuran,
R.A.Gravel.
|
|
|
Ref.
|
|
Genomics, 1988,
3,
279-286.
|
|
|
PubMed id
|
|
|
|
|
|
|
|
|
Secondary reference #2
|
|
|
Title
|
|
|
|
|
Author
|
|
I.Tews.
|
|
|
Ref.
|
|
serratia marcescens ...
|
|
|
|
|
|
|
|
