N-terminal putative catalytic domain of mainly uncharacterized prokaryotic proteins similar to archaeal thermoactive amylopullulanases; glycoside hydrolase family 57 (GH57)
This subfamily of mainly uncharacterized bacterial proteins, shows high sequence homology to GH57 archaeal thermoactive amylopullulanases (APU, E.C 3.2.1.1/41). Thermoactive APUs are type II pullulanases with both pullulanolytic and amylolytic activities. They have an acid pH optimum and the presence of Ca2+ might increase their activity, thermostability, and substrate affinity.
Jiyao W et al.(2023). "The conserved domain database in 2023.",