New Polysaccharide with a Long Evolutionary History.

Neofunctionalization could have occurred when the modern rosette-shaped cellulose synthase complex evolved near the base of the charophytic algae, making linear terminal complex cellulose synthases redundant. Cellulose synthase has a prokaryotic origin, and the arabinoglucan synthase, AGlcS, is strikingly similar to the prokaryotic homologs as well as cellulose synthases in fungi, oomycetes, and even a few animals. The discovery of the mixed-linkage arabinoglucan presents us with the only known polysaccharide synthesized by a member of the cellulose synthase superfamily featuring both hexosyl and pentosyl residues in its backbone. [Extracted from the article]