title: Plants, humans and hemoglobins.
abstract: New developments have forced a re-evaluation of our understanding of the structure and function of hemoglobins. Leghemoglobins regulate oxygen affinity through a mechanism different from that of myoglobin using a novel combination of heme pocket amino acids that lower the oxygen affinity. The hexacoordinate hemoglobins are characterized by intramolecular coordination of the ligand binding site at the heme iron, and were first identified in plants as the 'non-symbiotic plant hemoglobins'. They are now known to be present in animals and bacteria. Many of these proteins are upregulated in both plants and animals during hypoxia or similar stresses. Therefore, there might be a common physiological function for hexacoordinate hemoglobins in plants and animals.
authors.affiliation: Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
authors.forename: Suman
authors.initials: S
authors.lastname: Kundu
authors.forename: James T
authors.initials: JT
authors.lastname: Trent
authors.forename: Mark S
authors.initials: MS
authors.lastname: Hargrove
mesh_terms: D000818:Animals; D015786:Cytochromes b5 / Q000737:chemistry; D006454:Hemoglobins / Q000737:chemistry*; D006801:Humans; D007874:Leghemoglobin / Q000737:chemistry*; D008958:Models, Molecular; D009211:Myoglobin / Q000737:chemistry; D018521:Plant Physiological Phenomena; D011487:Protein Conformation
chemical_list: D006454:Hemoglobins; D007874:Leghemoglobin; D009211:Myoglobin; D015786:Cytochromes b5