Fucoidan-active a-L-fucosidases of the GH29 and GH95 families from a fucoidan degrading cluster of the marine bacterium Wenyingzhuangia fucanilytica

In present work we provide the bioinformatic and biochemical characterization of six alpha-L-fucosidases that belong to the 29 and 95 families of glycoside hydrolases (GH) from the fucoidan-degrading locus of the marine bac-terium Wenyingzhuangia fucanilytica CZ1127(T). The fucosidases FucWf1(GH29), FucWf2(GH29), FucWf3(GH29) and FucWf6(GH29 )are relegated to the subfamily A of the GH29 family. The fucosidase FucWf4(GH29) bears a distant resemblance to the GH29 and does not belong to either the GH29A or the GH29B subfamilies. Apparently, FucWf4(GH29) is the first representative of a new subfamily within the GH29 family of alpha-L-fucosidases. For the first time the specificity of fucosidases has been studied using a series of fucoidan-related sulfated oligosaccharides. Studied alpha-L-fucosidases are able to cleave L-fucose from sulfated fucooligosacchrides after their treatment with exo-sulfatases. All studied alpha-L-fucosidases are cleaving the alpha-1 -> 3-and alpha-1 -> 4-linked terminal L-fucose in sulfated fucooligosaccharides. However, only FucWf3(GH29) is able to cleave off an alpha-1 -> 2-linked L-fucose. The fucosidase FucWf5(GH95 )of the GH95 family is shown to have higher activity on fucoidans than fucosidases of the GH29 family. Supposedly, the alpha-L-fucosidase FucWf5(GH95) participates in fucoidan debranching. The obtained data indicate different roles of fucosidases of the GH29 and GH95 families in the process of fucoidan degradation by the marine bacteria W. fucanilytica CZ1127(T).

Automated summary

In this study, we characterized six alpha-L-fucosidases from the fucoidan-degrading locus of Wenyingzhuangia fucanilytica CZ1127(T) and found that they belong to the GH29 and GH95 families. These enzymes play different roles in the degradation of fucoidan by the marine bacterium.