[Structural and functional analysis of GH57 family thermostable amylopullulanase--a review].

Amylopullulanse (E. C. 3.2. 1. 1/41) has the enzymatic activities of both alpha-amylase (E. C. 3.2. 1. 1) and pullulanase (E. C. 3. 2. 1. 41), and is classified into the glycoside hydrolase 13 and 57 families. Amylopullulanse can hydrolyze both the alpha-1,4 and alpha-1,6 glucosidic bonds and is valuable for decreasing cost, increasing both efficiency and dextrose equivalent in starch processing industry. Thermostable amylopullulanase is more valuable in starch saccharification industry due to its capability to catalyze both the liquefaction and saccharification processes under the industrial starch liquefaction condition. In addition, the special bifunctional catalytic mechanism of amylopullulanase is also of great value in enzymology research. The present review focuses on the structure and function of amylopullulanases and provides a brief overview on the latest studies.