Component of the GPI transamidase complex. Involved in transfer of GPI to proteins. Glycolipid biosynthesis; glycosylphosphatidylinositol-anchor biosynthesis. Forms a complex with CDC91, GPI17, GPI8 and GAA1. The disulfide bond between GPI8 and GPI16 is important for normal enzyme activity. Present with 1680 molecules/cell in log phase SD medium. Belongs to the PIGT family. It is uncertain whether Met-1 or Met-9 is the initiator.