Major isoform of glycerol-1-phosphate phosphohydrolase involved in glycerol biosynthesis. Plays a role in osmoadaptation and required for adaptation to anaerobic conditions. H2O + sn-glycerol 1-phosphate = glycerol + phosphate H2O + sn-glycerol 3-phosphate = glycerol + phosphate Optimum pH is 6.5. Monomer. In response to both anaerobic and osmotic stress. Expression seems to be under the control of YIG1. Leads to osmosensitivity. Present with 193000 molecules/cell in log phase SD medium. Belongs to the HAD-like hydrolase superfamily. DOG/GPP family. Extended N-terminus.