The structure of murine neuroglobin: Novel pathways for ligand migration and binding

• DOI: 10.1002/prot.20113
• Publication Date: 2004-05-07T16:00:49Z
• Authors: Beatrice Vallone; Karin Nienhaus; Maurizio Brunori; G. Ulrich Nienhaus
• Keywords: Neuroglobin

Abstract Neuroglobin, a recently discovered globin predominantly expressed in neuronal tissue of vertebrates, binds small, gaseous ligands at the sixth coordination position heme iron. In absence an exogenous ligand, distal histidine (His64) to iron ferrous and ferric states. The crystal structure murine (met) neuroglobin 1.5 Å reveals interesting features relevant ligand binding mechanism. Only weak selectivity is observed for two possible orientations, occupancy ratio being 70:30. Two small internal cavities are present on side, which enable His64(E7) side chain move out way upon binding. Moreover, third, huge cavity (volume approximately 290 3 ) connecting both sides heme, open towards exterior provides potential passageway ligands. CD EF corners exhibit substantial flexibility, may assist entering protein accessing active site. Based this high‐resolution structure, further structure‐function studies can be planned elucidate role physiological responses hypoxia. Proteins 2004. © 2004 Wiley‐Liss, Inc.