Beta-agarase, member of glycosyl hydrolase family 16. Beta-agarase is a glycosyl hydrolase family 16 (GH16) member that hydrolyzes the internal beta-1,4-linkage of agarose, a hydrophilic polysaccharide found in the cell wall of Rhodophyceaea, marine red algae. Agarose is a linear chain of galactose units linked by alternating L-alpha-1,3- and D-beta-1,4-linkages that are additionally modified by a 3,6-anhydro-bridge. Agarose forms thermo-reversible gels that are widely used in the food industry or as a laboratory medium. While beta-agarases are also found in two other families derived from the sequence-based classification of glycosyl hydrolases (GH50, and GH86) the GH16 members are most abundant. This domain adopts a curved beta-sandwich conformation, with a tunnel-shaped active site cavity, referred to as a jellyroll fold.
glycosyl hydrolase family 16. The O-Glycosyl hydrolases are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A glycosyl hydrolase classification system based on sequence similarity has led to the definition of more than 95 different families inlcuding glycosyl hydrolase family 16. Family 16 includes lichenase, xyloglucan endotransglycosylase (XET), beta-agarase, kappa-carrageenase, endo-beta-1,3-glucanase, endo-beta-1,3-1,4-glucanase, and endo-beta-galactosidase, all of which have a conserved jelly roll fold with a deep active site channel harboring the catalytic residues.
Laminarinase, member of the glycosyl hydrolase family 16. Laminarinase, also known as glucan endo-1,3-beta-D-glucosidase, is a glycosyl hydrolase family 16 member that hydrolyzes 1,3-beta-D-glucosidic linkages in 1,3-beta-D-glucans such as laminarins, curdlans, paramylons, and pachymans, with very limited action on mixed-link (1,3-1,4-)-beta-D-glucans.
DNRLRE domain. The DNRLRE domain, with a length of about 160 amino acids, appears typically in large, repetitive surface proteins of bacteria and archaea, sometimes repeated several times. It occurs, notably, three times in the C-terminal region of the enzyme disaggregatase from the archaeal species Methanosarcina mazei, each time with the motif DNRLRE, for which the domain is named. Archaeal proteins within this family are described particularly well by the currently more narrowly defined Pfam model, PF06848. Note that the catalytic region of disaggregatase, in the N-terminal portion of the protein, is modeled by a different HMM, PF08480.
Kappa-carrageenase, member of glycosyl hydrolase family 16. Kappa-carrageenase is a glycosyl hydrolase family 16 (GH16) member that hydrolyzes the internal beta-1,4-linkage of kappa-carrageenans, a hydrophilic polysaccharide found in the cell wall of Rhodophyceaea, marine red algae. Carrageenans are linear chains of galactose units linked by alternating D-alpha-1,3- and D-beta-1,4-linkages that are additionally modified by a 3,6-anhydro-bridge. Depending on the position and number of sulfate ester modifications they are subdivided into kappa-, iota-, and lambda-carrageenases, kappa being modified once. Carrageenans form thermo-reversible gels widely used for industrial applications. Kappa-carrageenases exist in bacteria belonging to at least three phylogenetically distant branches, including pseudoalteromonas, planctomycetes, and baceroidetes. This domain adopts a curved beta-sandwich conformation, with a tunnel-shaped active site cavity, referred to as a jellyroll fold.