Back to Search
Start Over
Active site complementation and hexameric arrangement in the GH family 29; a structure–function study of α-l-fucosidase isoenzyme 1 from Paenibacillus thiaminolyticus.
- Source :
-
Glycobiology . Jan2019, Vol. 29 Issue 1, p59-73. 15p. - Publication Year :
- 2019
-
Abstract
- α- l -Fucosidase isoenzyme 1 from bacterium Paenibacillus thiaminolyticus is a member of the glycoside hydrolase family GH29 capable of cleaving l -fucose from nonreducing termini of oligosaccharides and glycoconjugates. Here we present the first crystal structure of this protein revealing a novel quaternary state within this family. The protein is in a unique hexameric assembly revealing the first observed case of active site complementation by a residue from an adjacent monomer in this family. Mutation of the complementing tryptophan residue caused changes in the catalytic properties including a shift of the pH optimum, a change of affinity to an artificial chromogenic substrate and a decreased reaction rate for a natural substrate. The wild-type enzyme was active on most of the tested naturally occurring oligosaccharides and capable of transglycosylation on a variety of acceptor molecules, including saccharides, alcohols or chromogenic substrates. Mutation of the complementing residue changed neither substrate specificity nor the preference for the type of transglycosylation acceptor molecule; however, the yields of the reactions were lower in both cases. Maltose molecules bound to the enzyme in the crystal structure identified surface carbohydrate-binding sites, possibly participating in binding of larger oligosaccharides. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09596658
- Volume :
- 29
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Glycobiology
- Publication Type :
- Academic Journal
- Accession number :
- 133582908
- Full Text :
- https://doi.org/10.1093/glycob/cwy078