1hxn
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1.8 ANGSTROMS CRYSTAL STRUCTURE OF THE C-TERMINAL DOMAIN OF RABBIT SERUM HEMOPEXIN
OverviewOverview
BACKGROUND: Haemopexin is a serum glycoprotein that binds haem reversibly, and delivers it to the liver where it is taken up by receptor-mediated, endocytosis. Haemopexin has two homologous domains, each having a, characteristic fourfold internal sequence repeat. Haemopexin-type domains, are also found in other proteins, including the serum adhesion protein, vitronectin and various collagenases, in which they mediate, protein-protein interactions. RESULTS: We have determined the crystal, structure of the C-terminal domain of haemopexin at 1.8 A resolution. The, domain is folded into four beta-leaflet modules, arranged in succession, around a central pseudo-fourfold axis. A funnel-shaped tunnel through the, centre of this disc-shaped domain serves as an ion-binding site., CONCLUSIONS: A model for haem binding by haemopexin is proposed, utilizing, an anion-binding site at the wider end of the central tunnel, together, with an associated cleft. This parallels the active-site location in other, beta-propeller structures. The capacity to bind both cations and anions, together with the disc shape of the domain, suggests that such domains may, be used widely for macromolecular recognition.
About this StructureAbout this Structure
1HXN is a Single protein structure of sequence from Oryctolagus cuniculus with PO4, NA and CL as ligands. Full crystallographic information is available from OCA.
ReferenceReference
1.8 A crystal structure of the C-terminal domain of rabbit serum haemopexin., Faber HR, Groom CR, Baker HM, Morgan WT, Smith A, Baker EN, Structure. 1995 Jun 15;3(6):551-9. PMID:8590016
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