Ulvan Lyases Isolated from the Flavobacteria Persicivirga ulvanivorans Are the First Members of a New Polysaccharide Lyase Family

• Published in: The Journal of biological chemistry 2011-12, Vol.286 (49), p.42063-42071
• Main Authors: Nyvall Collén, Pi, Sassi, Jean-François, Rogniaux, Hélène, Marfaing, Hélène, Helbert, William
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Carbohydrate Conformation; Carbohydrate Sequence; Cell Wall; Cell Wall - metabolism; Chlorophyta - metabolism; Chromatography, High Pressure Liquid; Chromatography, Liquid - methods; Cloning, Molecular; Enzyme Degradation; Enzyme Kinetics; Enzyme Purification; Enzymes - chemistry; Enzymology; Glucuronic Acid; Glucuronic Acid - chemistry; Green Algae; Iduronic Acid; Iduronic Acid - chemistry; Kinetics; Life Sciences; Magnetic Resonance Spectroscopy; Molecular Sequence Data; Peptides - chemistry; Polysaccharide; Polysaccharide Lyases; Polysaccharide-Lyases - chemistry; Tandem Mass Spectrometry - methods; Ulva - chemistry; Ulvan
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M111.271825

Ulvans are complex sulfated polysaccharides found in the cell walls of green algae belonging to the genus Ulva. These polysaccharides are composed of disaccharide repetition moieties made up of sulfated rhamnose linked to either glucuronic acid, iduronic acid, or xylose. Two ulvan lyases of 30 and 46 kDa were purified from the culture supernatant of Persicivirga ulvanivorans. Based on peptide sequencing, the gene encoding the 46-kDa ulvan lyase was cloned. Sequence analysis revealed that the protein is modular and possesses a catalytic module similar to that of the 30-kDa ulvan lyase along with a module of unknown function. The ulvan-degrading function of the gene was confirmed by expression of the catalytic module in a heterologous system. The gene encoding the catalytic module has no sequence homolog in sequence databases and is likely to be the first member of a novel polysaccharide lyase family. Analysis of degradation products showed that both the 30- and 46-kDa ulvan lyases are endolytic and cleave the glycosidic bond between the sulfated rhamnose and a glucuronic or iduronic acid. Background: Ulvan, an anionic polysaccharide, is the most abundant component of the green algal cell wall. Results: The isolated ulvan lyases cleave the glycosidic linkage of ulvan between IduA/GlcA and Rha3S. The gene sequence has no homology in databases. Conclusion: Ulvan lyases are the first members of a new polysaccharide lyase family. Significance: Characterization of ulvan lyase is a first step toward understanding the degradation of ulvan.