TextToBeDisplayed</scene>'>This hormone weight 30.4kD and is constituted to 166 amino acids.
It is composed to 4 alpha-helix: αA, αB, αC and αD which are associated the some in front of the others.
αA et αD are held together by a disulfide bond between and .
αB et αC are held together by a short loop.
The molecule of Erythropoietin have two opposite binding sites with his receptor. The first site include segments of αA, αB and αD and a part of the loop which connects αA and αB. This site include a hydrophobic center which interact with the receptor.
The Phenylalanine 93 of the receptor is critical important for binding of Erythropoietin to his receptor thanks to hydrogen bonds with residues Threonine 44 and Asparagine 147 of Erythropoietin.
