Molecular basis of arabinobio-hydrolase activity in phytopathogenic fungi: crystal structure and catalytic mechanism of Fusarium graminearum GH93 exo-alpha-L-arabinanase.

ABSTRACT: The phytopathogenic fungus Fusarium graminearum secretes a very diverse pool of glycoside hydrolases (GHs) aimed at degrading plant cell walls. alpha-l-Arabinanases are essential GHs participating in the complete hydrolysis of hemicellulose, a natural resource for various industrial processes, such as bioethanol or pharmaceuticals production. Arb93A, the exo-1,5-alpha-l-arabinanase of F. graminearum encoded by the gene fg03054.1, belongs to the GH93 family, for which no structural data exists. The enzyme is highly active (1065 units/mg) and displays a strict substrate specificity for linear alpha-1,5-l-arabinan. Biochemical assays and NMR experiments demonstrated that the enzyme releases alpha-1,5-l-arabinobiose from the nonreducing end of the polysaccharide. We determined the crystal stru

SUBMITTER: Carapito R 

PROVIDER: S-EPMC2673297 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature