Download MendeleyThe mechanism by which a distinguishing arabinofuranosidase can cope with internal di-substitutions in arabinoxylans.
Dos Santos, C.R., de Giuseppe, P.O., de Souza, F.H.M., Zanphorlin, L.M., Domingues, M.N., Pirolla, R.A.S., Honorato, R.V., Tonoli, C.C.C., de Morais, M.A.B., de Matos Martins, V.P., Fonseca, L.M., Buchli, F., de Oliveira, P.S.L., Gozzo, F.C., Murakami, M.T.(2018) Biotechnol Biofuels 11: 223-223
- PubMed: 30127853 Search on PubMedSearch on PubMed Central
- DOI: https://doi.org/10.1186/s13068-018-1212-y
- Primary Citation Related Structures:
6D25 - PubMed Abstract:
Arabinoxylan is an abundant polysaccharide in industrially relevant biomasses such as sugarcane, corn stover and grasses. However, the arabinofuranosyl di-substitutions that decorate the xylan backbone are recalcitrant to most known arabinofuranosidases (Abfs). In this work, we identified a novel GH51 Abf ( Xac Abf51) that forms trimers in solution and can cope efficiently with both mono- and di-substitutions at terminal or internal xylopyranosyl units of arabinoxylan. Using mass spectrometry, the kinetic parameters of the hydrolysis of 3 3 -α-l-arabinofuranosyl-xylotetraose and 2 3 ,3 3 -di-α-l-arabinofuranosyl-xylotetraose by Xac Abf51 were determined, demonstrating the capacity of this enzyme to cleave arabinofuranosyl linkages of internal mono- and di-substituted xylopyranosyl units. Complementation studies of fungal enzyme cocktails with Xac Abf51 revealed an increase of up to 20% in the release of reducing sugars from pretreated sugarcane bagasse, showing the biotechnological potential of a generalist GH51 in biomass saccharification. To elucidate the structural basis for the recognition of internal di-substitutions, the crystal structure of Xac Abf51 was determined unveiling the existence of a pocket strategically arranged near to the - 1 subsite that can accommodate a second arabinofuranosyl decoration, a feature not described for any other GH51 Abf structurally characterized so far. In summary, this study reports the first kinetic characterization of internal di-substitution release by a GH51 Abf, provides the structural basis for this activity and reveals a promising candidate for industrial processes involving plant cell wall depolymerization.
- 1Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center for Research in Energy and Materials (CNPEM), Campinas, Sao Paulo 13083-970 Brazil.
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