title: Investigating the function of an arabinan utilization locus isolated from a termite gut community.
abstract: Biocatalysts are essential for the development of bioprocesses efficient for plant biomass degradation. Previously, a metagenomic clone containing DNA from termite gut microbiota was pinpointed in a functional screening that revealed the presence of arabinofuranosidase activity. Subsequent genetic and bioinformatic analysis revealed that the DNA fragment belonged to a member of the genus Bacteroides and encoded 19 open reading frames (ORFs), and annotation suggested the presence of hypothetical transporter and regulator proteins and others involved in the catabolism of pentose sugar. In this respect and considering the phenotype of the metagenomic clone, it was noted that among the ORFs, there are four putative arabinose-specific glycoside hydrolases, two from family GH43 and two from GH51. In this study, a thorough bioinformatics analysis of the metagenomic clone gene cluster has been performed and the four aforementioned glycoside hydrolases have been characterized. Together, the results provide evidence that the gene cluster is a polysaccharide utilization locus dedicated to the breakdown of the arabinan component in pectin and related substrates. Characterization of the two GH43 and the two GH51 glycoside hydrolases has revealed that each of these enzymes displays specific catalytic capabilities and that when these are combined the enzymes act synergistically, increasing the efficiency of arabinan degradation.
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Arnal
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Bastien
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Nelly
authors.initials: N
authors.lastname: Monties
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Abot
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Anton Leberre
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Sophie
authors.initials: S
authors.lastname: Bozonnet
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France.
authors.forename: Michael
authors.initials: M
authors.lastname: O'Donohue
authors.affiliation: Université de Toulouse, INSA, UPS, INP, LISBP, Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, Toulouse, France; CNRS, UMR5504, Toulouse, France claire.dumon@insa-toulouse.fr.
authors.forename: Claire
authors.initials: C
authors.lastname: Dumon
mesh_terms: D000818:Animals; D001439:Bacteroides / Q000235:genetics* / Q000378:metabolism*; D019295:Computational Biology; D041981:Gastrointestinal Tract / Q000382:microbiology; D006026:Glycoside Hydrolases / Q000235:genetics; D020049:Isoptera / Q000382:microbiology*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D056186:Metagenomics; D005810:Multigene Family; D011134:Polysaccharides / Q000378:metabolism*
chemical_list: D011134:Polysaccharides; C030080:araban; D006026:Glycoside Hydrolases