Phosphoglycerate mutase-like protein lacking PGM activity, but having 2-carboxy-D-arabinitol 1-phosphate (CA1P) phosphatase activity. Can dephosphorylate the closely related compounds 2-carboxy-D-arabinitol 1,5-bisphosphate (CABP) and 2-carboxy-D-ribitol-1,5-bisphosphate(CRBP), and 2,3-diphosphoglycerate. 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 Inactivated by oxidized glutathione (GSSG) at pH 8.0. Optimum pH is 7.0. Belongs to the phosphoglycerate mutase family.