Phosphatase catalytic subunit of the trehalose synthase complex that catalyzes the production of trehalose from glucose-6-phosphate and UDP-alpha-D-glucose in a two step process. alpha,alpha-trehalose 6-phosphate + H2O = alpha,alpha-trehalose + phosphate Inhibited by EDTA. Optimum pH is 6.0. Carbohydrate biosynthesis. The trehalose synthase complex is composed of the two catalytic subunits TPS1 and TPS2, and at least one of the two regulatory subunits TPS3 or TSL1. By heat shock. Repressed by glucose. Present with 22700 molecules/cell in log phase SD medium. In the N-terminal section; belongs to the glycosyltransferase 20 family. In the C-terminal section; belongs to the trehalose phosphatase family.