Structure-function relationships in the growing hexa-coordinate hemoglobin sub-family.
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.
de Sanctis
Daniele
D
Department of Physics-INFM, Center for Excellence in Biomedical Research, University of Genova, Via Dodecaneso 33, I-16146 Genova, Italy.
Pesce
Alessandra
A
Nardini
Marco
M
Bolognesi
Martino
M
Bocedi
Alessio
A
Ascenzi
Paolo
P
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
D006454:Hemoglobins; D008024:Ligands; D006418:Heme