This family contains several bacterial alginate lyase proteins. Alginate is a family of 1-4-linked copolymers of beta -D-mannuronic acid (M) and alpha -L-guluronic acid (G). It is produced by brown algae and by some bacteria belonging to the genera Azotobacter and Pseudomonas. Alginate lyases catalyse the depolymerisation of alginates by beta -elimination, generating a molecule containing 4-deoxy-L-erythro-hex-4-enepyranosyluronate at the nonreducing end [1]. This family adopts an all alpha fold [2].

1: Biochemical properties and substrate specificities of a recombinantly produced Azotobacter vinelandii alginate lyase. Ertesvag H, Erlien F, Skjak-Braek G, Rehm BH, Valla S; J Bacteriol 1998;180:3779-3784. PMID:9683471

2: Crystal structure of alginate lyase A1-III from Sphingomonas species A1 at 1.78 A resolution. Yoon HJ, Mikami B, Hashimoto W, Murata K; J Mol Biol 1999;290:505-514. PMID:10390348