Two types of receptors for iron on mitochondria

Abstract

ATP, the major ligand for Fe in the reticulocyte's low-Mr chelatable pool, transfers Fe to a mitochondrial receptor from which the Fe is incorporated into haem. However, the utilization of Fe bound to this receptor for haem synthesis is slow in comparison with that bound to a second receptor that does not accept Fe from ATP, but does accept it from AMP. The major pathway by which Fe is delivered for haem synthesis may be through hydrolysis of cytosolic ATP-Fe to AMP-Fe.