cDNA cloning and bacterial expression of a PL-14 alginate lyase from a herbivorous marine snail Littorina brevicula

► The cDNA encoding an alginate lyase, named LbAly28, was cloned from Littorina brevicula. ► The deduced amino-acid sequence analysis revealed that LbAly28 belongs to PL-14 family. ► Catalytic residues of LbAly28 were identified by site-directed mutagenesis. ► These residues coincide with those in the active site of Chlorella virus vAL-1. ► Replacement of Thr121 to Ala was found to result changes in substrate preference of this enzyme.