Phosphoglycerate mutase

1yfkA:5-193 1ljdA:5-193 1fztA:9-170 4pgmB:3-189 3pgmB:3-189 1qhfA:3-189 1bq3B:3-189 1bq4B:3-189 1riiA:6-190 1t8pA:5-195 1h2eA:2-151 1h2fA:2-151 1ebbA:2-151 2bifA:251-398 3bifA:251-398 1bif :251-398 1k6mB:253-400 1c80A:253-400 1c7zA:253-400 1fbtB:253-400 1c81A:253-400 Phosphoglycerate mutase (PGM) is any enzyme that catalyzes step 8 of glycolysis - the internal transfer of a phosphate group from C-3 to C-2 which results in the conversion of 3-phosphoglycerate (3PG) to 2-phosphoglycerate (2PG) through a 2,3-bisphosphoglycerate intermediate.

In the cofactor-dependent enzyme's initial state, the active site contains a phosphohistidine complex formed by phosphorylation of a specific histidine residue.

[9] When 3-phosphoglycerate enters the active site, the phosphohistidine complex is positioned as to facilitate transfer of phosphate from enzyme to substrate C-2 creating a 2,3-bisphosphoglycerate intermediate.

In mammals, the enzyme subunits appear to be either a muscle-derived form (m-type) or other tissue (b-type for brain where the b-isozyme was originally isolated).

Existing as a dimer, the enzyme then has 3 isozymes depending on which subunit forms makeup the whole molecule (mm, bb or mb).

Anionic molecules such as vanadate,[12] acetate, chloride ion, phosphate, 2-phosphoglycolate, and N-[tris(hydroxymethyl)methyl-2-amino]ethanesulfonate are known inhibitors of the mutase activity of dPGM.

Deficiency of phosphoglycerate mutase causes glycogen storage disease type X, a rare autosomal recessive genetic disorder with symptoms ranging from mild to moderate; is not thought life-threatening and can be managed with changes in lifestyle.

Patients with PGAM deficiency are usually asymptomatic, except when they engage in brief, strenuous efforts which may trigger myalgias, cramps, muscle necrosis and myoglobinuria.