Key Residues for Haem Binding
| α-chain |
β-chain |
| Lys61Nζ→Haem Ala65 CβH: 3.756Å |
Lys66Nζ→Haem Ala65 CβH: 3.294Å |
| (no H bond shown) |
H-bond from Lys66Nζ→Haem Ala65 CβH |
| α-chain: measured from HisNε |
β-chain: measured from HisNε |
| His 58→O1: 2.533Å |
His63→O1: 3.126Å |
| His58→O2:3.075Å |
His63→O2: 2.681Å |
| His58→Fe: 4.516Å |
His63→Fe:4.508Å |
| His87→Fe: 2.104Å |
His92: 2.074Å) |
| Distance from His58Nε↔His87Nε: 6.396Å |
Distance from His63Nε↔His92Nε: 6.312Å |
aHis87 and bHis92 make contact with the haem group Fe atom. bLys66 forms a Hydrogen bond with the haem group. The equivalent residue in the a-chain,aLys61, may also form a weaker interaction with the haem group, but is located at the greater distance of 3.57Å.