Active site complementation and hexameric arrangement in the GH family 29, a structure-function study of alpha-l-fucosidase isoenzyme 1 from Paenibacillus thiaminolyticus

0510112 - BTÚ 2020 RIV US eng J - Journal Article
Koval'ová, Terezia - Koval, Tomáš - Benešová, E. - Vodickova, P. - Spiwok, V. - Lipovová, P. - Dohnálek, Jan
Active site complementation and hexameric arrangement in the GH family 29, a structure-function study of alpha-l-fucosidase isoenzyme 1 from Paenibacillus thiaminolyticus.
Glycobiology. Roč. 29, č. 1 (2019), s. 59-73. ISSN 0959-6658. E-ISSN 1460-2423
R&D Projects: GA MŠMT(CZ) LM2015043; GA MŠMT(CZ) EF16_013/0001776; GA MŠMT(CZ) ED1.1.00/02.0109
Institutional support: RVO:86652036
Keywords : crystal structure * Paenibacillus thiaminolyticus * glycosidase * alpha-l-fucosidase
OECD category: Biochemistry and molecular biology
Impact factor: 4.060, year: 2019
Method of publishing: Open access
https://academic.oup.com/glycob/article/29/1/59/5078562

alpha-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.
Permanent Link: http://hdl.handle.net/11104/0300667