title: Cloning and characterization of arabinoxylan arabinofuranohydrolase-D3 (AXHd3) from Bifidobacterium adolescentis DSM20083.
abstract: Arabinoxylan arabinofuranohydrolase-D3 (AXHd3) from Bifidobacterium adolescentis releases only C3-linked arabinose residues from double-substituted xylose residues. A genomic library of B. adolescentis DSM20083 was screened for the presence of the axhD3 gene. Two plasmids were identified containing part of the axhD3 gene. The nucleotide sequences were combined and three open reading frames (ORFs) were found. The first ORF showed high homology with xylanases belonging to family 8 of the glycoside hydrolases and this gene was designated xylA. The second ORF was the axhD3 gene belonging to glycoside hydrolase family 43. The third (partial) ORF coded for a putative carboxylesterase. The axhD3 gene was cloned and expressed in Escherichia coli. Several substrates were employed in the biochemical characterization of recombinant AXHd3. The enzyme showed the highest activity toward wheat arabinoxylan oligosaccharides. In addition, beta-xylanase from Trichoderma sp. was able to degrade soluble wheat arabinoxylan polymer to a higher extent, after pretreatment with recombinant AXHd3. Arabinoxylan oligosaccharides incubated with a combination of recombinant AXHd3 and an alpha-L-arabinofuranosidase from Aspergillus niger did not result in a higher maximal release of arabinose than incubation with these enzymes separately.
authors.affiliation: Laboratory of Food Chemistry, Wageningen University, P.O. Box 8129, Wageningen, EV 6700, The Netherlands.
authors.forename: Lambertus A M
authors.initials: LA
authors.lastname: van den Broek
authors.forename: Ruth M
authors.initials: RM
authors.lastname: Lloyd
authors.forename: Gerrit
authors.initials: G
authors.lastname: Beldman
authors.forename: Jan C
authors.initials: JC
authors.lastname: Verdoes
authors.forename: Barry V
authors.initials: BV
authors.lastname: McCleary
authors.forename: Alphons G J
authors.initials: AG
authors.lastname: Voragen
mesh_terms: D001089:Arabinose / Q000378:metabolism; D001234:Aspergillus niger / Q000201:enzymology; D001644:Bifidobacterium / Q000201:enzymology* / Q000235:genetics; D043182:Carboxylesterase / Q000235:genetics; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D043364:Endo-1,4-beta Xylanases / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D006026:Glycoside Hydrolases / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D013379:Substrate Specificity; D014242:Trichoderma / Q000201:enzymology
chemical_list: D004269:DNA, Bacterial; D011994:Recombinant Proteins; D001089:Arabinose; D043182:Carboxylesterase; D006026:Glycoside Hydrolases; C019713:alpha-N-arabinofuranosidase; D043364:Endo-1,4-beta Xylanases