TABLE 3.

Properties of the cold-adapted enzymes from Sde 2-40 and the frequencies of charged amino acid residues for CBM.

Enzyme	SdG5A	Aga50D	Xyn10C
Properties	Retain ∼30% of its maximum activity at 4°C	Retain ∼78% of its maximum activity at 20°C	Retain ∼80% of its maximum activity at 20°C
Acidic residues (%)	9.3	12.9	13.9
Basic residues (%)	5.2	9.3	4.9
Net charge density (z, %)a	−4.1	−3.6	−9.0

^aNet charge density is estimated by z = (n_basic - n_acidic)/length × 100%, where n_basic and n_acidic are the number of basic and acidic residues, respectively. Acidic residues include glutamic acid and aspartic acid. Basic residues include histidine, lysine, and arginine. All sequences are presented in the Supplementary Material. Aga50D, β-agarase from Saccharophagus degradans 2-40^T; Xyn10C, β-glycosidase from Saccharophagus degradans 2-40^T.