Crystal structures of Parasponia and Trema hemoglobins: differential heme coordination is linked to quaternary structure.
Kakar, S., Sturms, R., Tiffany, A., Nix, J.C., DiSpirito, A.A., Hargrove, M.S.(2011) Biochemistry 50: 4273-4280
- PubMed: 21491905 
- DOI: 10.1021/bi2002423
- Primary Citation of Related Structures:  
3QQQ, 3QQR - PubMed Abstract: 
Hemoglobins from the plants Parasponia andersonii (ParaHb) and Trema tomentosa (TremaHb) are 93% identical in primary structure but differ in oxygen binding constants in accordance with their distinct physiological functions. Additionally, these proteins are dimeric, and ParaHb exhibits the unusual property of having different heme redox potentials for each subunit ...