Characterization of a novel endo-1,3-fucanase from marine bacterium Wenyingzhuangia fucanilytica reveals the presence of diversity within glycoside hydrolase family 168

Sulfated fucans attract increasing research interests in recent decades for their various physiological activities. Fucanases are indispensable tools for the investigation of sulfated fucans. Herein, a novel GH168 family endo1,3-fucanase was cloned from the genome of marine bacterium Wenyingzhuangia fucanilytica. The expressed protein Fun168D was a processive endo-acting enzyme. Ultra performance liquid chromatography-high resolution mass spectrum and NMR analyses revealed that the enzyme cleaved the & alpha;-1 -* 3 bonds between & alpha;-L-Fucp (2OSO3  ) and & alpha;-L-Fucp(2OSO3  ) in sulfated fucan from Isostichopus badionotus, and & alpha;-1 -* 3 bonds between & alpha;-LFucp(2OSO3  ) and & alpha;-L-Fucp(2,4OSO3  ) in sulfated fucan from Holothuria tubulosa. Fun168D would prefer to accept & alpha;-L-Fucp(2,4OSO3  ) than & alpha;-L-Fucp(2OSO3  ) at subsite +1, and could tolerate the absence of fucose residue at subsite +2. The novel cleavage specificity and hydrolysis pattern revealed the presence of diversity within the GH168 family, which would facilitate the development of diverse biotechnological tools for the molecule tailoring of sulfated fucan.