A β-mannan utilization locus in Bacteroides ovatus involves a GH36 α-galactosidase active on galactomannans.
The Bacova_02091 gene in the β-mannan utilization locus of Bacteroides ovatus encodes a family GH36 α-galactosidase (BoGal36A), transcriptionally upregulated during growth on galactomannan. Characterization of recombinant BoGal36A reveals unique properties compared to other GH36 α-galactosidases, which preferentially hydrolyse terminal α-galactose in raffinose family oligosaccharides. BoGal36A prefers hydrolysing internal galactose substitutions from intact and depolymerized galactomannan. BoGal36A efficiently releases (> 90%) galactose from guar and locust bean galactomannans, resulting in precipitation of the polysaccharides. As compared to other GH36 structures, the BoGal36A 3D model displays a loop deletion, resulting in a wider active site cleft which likely can accommodate a galactose-substituted polymannose backbone.
Department of Biochemistry and Structural Biology, Lund University, Sweden.
Sumitha K
SK
Reddy
Department of Biochemistry and Structural Biology, Lund University, Sweden.
Viktoria
V
Bågenholm
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
Nicholas A
NA
Pudlo
Department of Biochemistry and Structural Biology, Lund University, Sweden.
Hanene
H
Bouraoui
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
Nicole M
NM
Koropatkin
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, MI, USA.
Eric C
EC
Martens
Department of Biochemistry and Structural Biology, Lund University, Sweden.
Henrik
H
Stålbrand
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001439:Bacteroides / Q000201:enzymology / Q000235:genetics; D005690:Galactose / Q000031:analogs & derivatives; D056426:Genetic Loci; D008351:Mannans / Q000378:metabolism*; D008954:Models, Biological; D000519:alpha-Galactosidase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D008351:Mannans; C012990:galactomannan; D000519:alpha-Galactosidase; D005690:Galactose
Bacteroides ovatus; GH36 α-galactosidase; galactomannan modification; polysaccharide utilization locus