Phosphoglycerate mutase-like protein lacking PGM activity, but having 2-carboxy-D-arabinitol 1-phosphate (CA1P) phosphatase activity. Prevents the accumulation of D-glycero-2,3-pentodiulose-1,5-bisphosphate (PDBP) a potent inhibitor of ribulose-1,5-bisphosphate carboxylase (RuBisCO). PDBP is produced during the oxidation of ribulose-1,5-bisphosphate, the substrate of RuBisCO. 2-carboxy-D-arabinitol 1-phosphate + H2O = 2-carboxy-D-arabinitol + phosphate A number of isoforms are produced. According to EST sequences. Belongs to the phosphoglycerate mutase family.