Members of this family are the trehalose biosynthetic enzyme malto-oligosyltrehalose trehalohydrolase, formally known as 4-alpha-D-{(1->4)-alpha-D-glucano}trehalose trehalohydrolase (EC 3.2.1.141). It is the TreZ protein of the TreYZ pathway for trehalose biosynthesis, and alternative to the OtsAB system. [Energy metabolism, Biosynthesis and degradation of polysaccharides]