The GH51 α-l-arabinofuranosidase from Paenibacillus sp. THS1 is multifunctional, hydrolyzing main-chain and side-chain glycosidic bonds in heteroxylans.

Authors Organisations
  • Hanen Bouraoui(Author)
    Université de Jendouba
  • Marie-Laure Desrousseaux(Author)
    University of Toulouse
  • Eleni Ioannou(Author)
  • Pablo Alvira(Author)
    University of Toulouse
  • Mohamed Manaï(Author)
    Université de Tunis El Manar
  • Caroline Rémond,(Author)
    National Institute of Agricultural Research
  • Claire Dumon(Author)
    National Institute of Agricultural Research
  • Narcis Fernandez Fuentes(Author)
  • Michael J. O'Donohue(Author)
Type Article
Original languageEnglish
Article number140
JournalBiotechnology for Biofuels
Publication statusPublished - 08 Jul 2016
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Conceptually, multi-functional enzymes are attractive because in the case of complex polymer hydrolysis having two or more activities defined by a single enzyme offers the possibility of synergy and reduced enzyme cocktail complexity. Nevertheless, multi-functional enzymes are quite rare and are generally multi-domain assemblies with each activity being defined by a separate protein module. However, a recent report described a GH51 arabinofuranosidase from Alicyclobacillus sp. A4 that displays both α-l-arabinofuranosidase and β-d-xylanase activities, which are defined by a single active site. Following on from this, we describe in detail another multi-functional GH51 arabinofuranosidase and discuss the molecular basis of multifunctionality.

THSAbf is a GH51 α-l-arabinofuranosidase. Characterization revealed that THSAbf is active up to 75 °C, stable at 60 °C and active over a broad pH range (4–7). THSAbf preferentially releases para-nitrophenyl from the l-arabinofuranoside (k cat/K M = 1050 s−1 mM−1) and to some extent from d-galactofuranoside and d-xyloside. THSAbf is active on 4-O-methylglucuronoxylans from birch and beechwood (10.8 and 14.4 U mg−1, respectively) and on sugar beet branched and linear arabinans (1.1 ± 0.24 and 1.8 ± 0.1 U mg−1). Further investigation revealed that like the Alicyclobacillus sp. A4 α-l-arabinofuranosidase, THSAbf also displays endo-xylanase activity, cleaving β-1,4 bonds in heteroxylans. The optimum pH for THASAbf activity is substrate dependent, but ablation of the catalytic nucleophile caused a general loss of activity, indicating the involvement of a single active center. Combining the α-l-arabinofuranosidase with a GH11 endoxylanase did not procure synergy. The molecular modeling of THSAbf revealed a wide active site cleft and clues to explain multi-functionality.

The discovery of single active site, multifunctional enzymes such as THSAbf opens up exciting avenues for enzyme engineering and the development of new biomass-degrading cocktails that could considerably reduce enzyme production costs


  • glycoside hydrolase, xylanase, wheat bran, enzyme cocktails, biomass