BPGM belongs to the phosphoglycerate mutase family, BPG-dependent PGAM subfamily. It plays a major role in regulating hemoglobin oxygen affinity as a consequence of controlling 2,3-BPG concentration. It can also catalyze the reaction of EC 5.4.2.1 (mutase) and EC 3.1.3.13 (phosphatase), but with a reduced activity.