Characterization of a hyperthermophilic phosphatase from Archaeoglobus fulgidus and its application in in vitro synthetic enzymatic biosystem

Abstract Background Haloacid dehalogenase (HAD)-like hydrolases represent the largest superfamily of phosphatases, which release inorganic phosphate from phosphate containing compounds, such as sugar phosphates. The HAD-like phosphatases with highly substrate specificity, which perform irreversible dephosphorylation, are always integrated into in vitro synthetic enzymatic biosystems as the last enzymatic step for the cost-efficient production of biochemicals. Therefore, identification and characterization of substrate specificity of HAD-like phosphatases are important for exploring their application. Results In this study, a hyperthermophilic HAD-like phosphatase from Archaeoglobus fulgidus (AfPase) was cloned, expressed, and characterized. AfPase was identified as a type I Mg2+-dependent HAD-like phosphatase with high optimal temperature and thermostability. Among the tested phosphate containing compounds, AfPase exhibited the highest catalytic activity on p-nitrophenyl phosphate, followed by dihydroxyacetone phosphate (DHAP). On the basis of the high catalytic activity of AfPase to generate 1,3-dihydroxyacetone (DHA) from DHAP, an in vitro synthetic enzymatic biosystem containing this phosphatase and other five enzymes was constructed for the biosynthesis of DHA from inexpensive maltodextrin in one pot. About 14 mM (1.26 g/L) DHA was produced from 10 g/L maltodextrin. Conclusions A hyperthermophilic HAD-like phosphatase from Archaeoglobus fulgidus was characterized carefully, and the success of an in vitro synthetic enzymatic biosystem containing this phosphatase provided a promising approach for DHA production from maltodextrin.