title: X-ray diffraction structure of a plant glycosyl hydrolase family 32 protein: fructan 1-exohydrolase IIa of Cichorium intybus.
abstract: Fructan 1-exohydrolase, an enzyme involved in fructan degradation, belongs to the glycosyl hydrolase family 32. The structure of isoenzyme 1-FEH IIa from Cichorium intybus is described at a resolution of 2.35 A. The structure consists of an N-terminal fivefold beta-propeller domain connected to two C-terminal beta-sheets. The putative active site is located entirely in the beta-propeller domain and is formed by amino acids which are highly conserved within glycosyl hydrolase family 32. The fructan-binding site is thought to be in the cleft formed between the two domains. The 1-FEH IIa structure is compared with the structures of two homologous but functionally different enzymes: a levansucrase from Bacillus subtilis (glycosyl hydrolase family 68) and an invertase from Thermotoga maritima (glycosyl hydrolase family 32).
authors.affiliation: Laboratorium voor Analytische Chemie en Medicinale Fysicochemie, Faculteit Farmaceutische Wetenschappen, K.U. Leuven, E. Van Evenstraat 4, B-3000 Leuven, Belgium.
authors.forename: Maureen
authors.initials: M
authors.lastname: Verhaest
authors.forename: Wim
authors.initials: W
authors.lastname: Van den Ende
authors.forename: Katrien Le
authors.initials: KL
authors.lastname: Roy
authors.forename: Camiel J
authors.initials: CJ
authors.lastname: De Ranter
authors.forename: André Van
authors.initials: AV
authors.lastname: Laere
authors.forename: Anja
authors.initials: A
authors.lastname: Rabijns
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology; D001665:Binding Sites; D018651:Cichorium intybus / Q000201:enzymology*; D017124:Conserved Sequence; D006026:Glycoside Hydrolases / Q000737:chemistry*; D006602:Hexosyltransferases / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D011487:Protein Conformation; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D020124:Thermotoga maritima / Q000201:enzymology; D014961:X-Ray Diffraction; D043324:beta-Fructofuranosidase / Q000737:chemistry
chemical_list: D006602:Hexosyltransferases; C021513:levansucrase; D006026:Glycoside Hydrolases; D043324:beta-Fructofuranosidase; C044118:fructan beta-fructosidase