title: Structure-function relationships in the growing hexa-coordinate hemoglobin sub-family.
abstract: Hemoglobin and related heme proteins, generally referred to as 'globins', reversibly bind gaseous diatomic ligands (O2, NO, and CO) to a penta-coordinate heme iron atom, the ligand filling the sixth coordination site. Over the last decade, several new globins have been reported to display a functionally-relevant hexa-coordinate heme iron atom, whose sixth coordination site is taken by an endogenous protein ligand. The reversible intramolecular hexa- to penta-coordination process at the heme-Fe atom modulates exogenous ligand binding properties of hexa-coordinate globins. Here, we review current knowledge on hexa-coordinate globins in terms of their structural and functional properties.
authors.affiliation: Department of Physics-INFM, Center for Excellence in Biomedical Research, University of Genova, Via Dodecaneso 33, I-16146 Genova, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: de Sanctis
authors.forename: Alessandra
authors.initials: A
authors.lastname: Pesce
authors.forename: Marco
authors.initials: M
authors.lastname: Nardini
authors.forename: Martino
authors.initials: M
authors.lastname: Bolognesi
authors.forename: Alessio
authors.initials: A
authors.lastname: Bocedi
authors.forename: Paolo
authors.initials: P
authors.lastname: Ascenzi
mesh_terms: D000818:Animals; D006418:Heme / Q000737:chemistry* / Q000502:physiology*; D006454:Hemoglobins / Q000737:chemistry* / Q000502:physiology*; D006801:Humans; D008024:Ligands; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D046939:Synechocystis / Q000502:physiology
chemical_list: D006454:Hemoglobins; D008024:Ligands; D006418:Heme