Marine Polysaccharide Sulfatases

Abstract

Polysaccharides are the most abundant and the most complex organic molecules in the ocean. In contrast to land polysaccharides, many marine polysaccharides are highly sulfated; in particular, the cell walls of macroalgae harbor a high diversity of sulfated polysaccharides (carrageenans, agarans, fucoidans, ulvans, etc.). These sulfated polysaccharides, biosynthesized by macroalgal primary producers, represent an important food source for heterotrophic organisms. Their biodegradation requires a set of enzymes that can cleave the glycosidic linkages of the carbohydrate backbone (called glycoside hydrolases) and the sulfate ester groups (called polysaccharide sulfatases). This review first provides on overview of the current state of knowledge on the classification and mechanisms of sulfatases in general. Then, based on an exploration of marine genomic and metagenomics data that reveals the diversity of carbohydrate sulfatases, it focuses on strategies to predict these sulfatases. In particular, the modularity of sulfatases and their location in marine polysaccharide utilization loci (PUL) provide clues as to their potential substrates and can drive future functional assays. Finally, the review underscores the low number of currently biochemically characterized marine carbohydrate sulfatases (e.g., agarases, carrageenanases, and fucose sulfatases). Bottlenecks encountered in studies on sulfatases likely lie in the difficulties in purifying them and producing them in heterologous systems.

Chemical Diversity and Biochemical Transformation of Biogenic Organic Sulfur in the Ocean

“…Sulfate esters provide bacteria with either sulfur or carbon source, and microorganisms have genes encoding sulfatase enzymes that catalyze the hydrolysis of sulfates from various sulfate esters. The choline-sulfatase (betC) catalyzes the hydrolysis of choline sulfate to choline (Østerås et al, 1998), while N-acetylglucosamine-6sulfatase (GNS) and N-acetylgalactosamine-6-sulfatase (GALNS) catalyze the hydrolysis of ester-bonded sulfur from heparan sulfate and chondroitin sulfate, respectively (Helbert, 2017).…”

Characterization of an Alteromonas long-type ulvan lyase involved in the degradation of ulvan extracted from Ulva ohnoi

“…Genes coding for proteins involved in the polysaccharide degradation pathway co-localize in a cluster referred to as the polysaccharide utilization loci (PUL). 25) We found many genes related to ulvan degradation surrounding UllA (unpublished data). Foran et al have clearly demonstrated that genes in the PUL of Alteromonas sp.…”

Metabolic relationships of uncultured bacteria associated with the microalgae Gambierdiscus

“…are lacking. PHY‐2, RHO‐5a and FLA‐8 may play roles in the degradation of these compounds through hydrolytic cleavage of sulfate esters catalysed by Type I sulfatases (Helbert, ). Sulfatases are common within the Planctomycetes (Wegner et al ., ), yet no sulfatases were identified within PHY‐1.…”