Sequence logos of α-amylases from studied GH13 subfamilies. Logos for (A) all the six studied subfamilies (268 sequences); (B) subfamily GH13_1 (39 sequences); (C) subfamily GH13_5 (35 sequences); (D) G13_15 (28 sequences); (E) subfamily GH13_24 (23 sequences); (F) subfamily GH13_32 (140 sequences); and (G) G13_42 (3 sequences). CSR-I, residues 13–18; CSR-II, residues 24–32; CSR-III, residues 33–40; CSR-IV, residues 41–46; CSR-V, residues 19–23; CSR-VI, residues 4–12; CSR-VII, residues 47–55; CSR-VIII, residues 1–3. The catalytic triad, i.e., the catalytic nucleophile (No. 28, aspartic acid in CSR-II), the proton donor (No. 37, glutamic acid in CSR-III) and the transition-state stabilizer (No. 46, aspartic acid in CSR-IV) are indicated by asterisks.