1oxy

CRYSTALLOGRAPHIC ANALYSIS OF OXYGENATED AND DEOXYGENATED STATES OF ARTHROPOD HEMOCYANIN SHOWS UNUSUAL DIFFERENCES

spinqualitylabelsall models 1oxy, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1oxy is a 1 chain structure with sequence from Atlantic horseshoe crab. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CU, OXY Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [HCY2_LIMPO] Hemocyanins are copper-containing oxygen carriers occurring freely dissolved in the hemolymph of many mollusks and arthropods. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The X-ray structure of an oxygenated hemocyanin molecule, subunit II of Limulus polyphemus hemocyanin, was determined at 2.4 A resolution and refined to a crystallographic R-factor of 17.1%. The 73-kDa subunit crystallizes with the symmetry of the space group R32 with one subunit per asymmetric unit forming hexamers with 32 point group symmetry. Molecular oxygen is bound to a dinuclear copper center in the protein's second domain, symmetrically between and equidistant from the two copper atoms. The copper-copper distance in oxygenated Limulus hemocyanin is 3.6 +/- 0.2 A, which is surprisingly 1 A less than that seen previously in deoxygenated Limulus polyphemus subunit II hemocyanin (Hazes et al., Protein Sci. 2:597, 1993). Away from the oxygen binding sites, the tertiary and quaternary structures of oxygenated and deoxygenated Limulus subunit II hemocyanins are quite similar. A major difference in tertiary structures is seen, however, when the Limulus structures are compared with deoxygenated Panulirus interruptus hemocyanin (Volbeda, A., Hol, W.G.J.J. Mol. Biol. 209:249, 1989) where the position of domain 1 is rotated by 8 degrees with respect to domains 2 and 3. We postulate this rotation plays an important role in cooperativity and regulation of oxygen affinity in all arthropod hemocyanins. Crystallographic analysis of oxygenated and deoxygenated states of arthropod hemocyanin shows unusual differences.,Magnus KA, Hazes B, Ton-That H, Bonaventura C, Bonaventura J, Hol WG Proteins. 1994 Aug;19(4):302-9. PMID:7984626 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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