TABLE 2.

Comparison of the frequencies of charged amino acid residues for different domains in SdG5A and other extremophilic amylases.

Parameter	SdG5A					AHA	ZPA
	Catalytic domain	Accessory domain	Linker	CBM	Entire protein
Acidic residues (%)	9.9	7.5	27.8	9.3	10.0	10.2	15.0
Basic residues (%)	11.7	8.6	5.6	5.2	9.8	7.8	11.8
Net charge density (z, %)a	1.6	1.1	−22.2	−4.1	−0.2	−2.8	−3.7

^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. AHA, α-amylase from Alteromonas haloplanctis; ZPA, α-amylase from Zunongwangia profunda.