1oxy
From Proteopedia
(New page: 200px<br /><applet load="1oxy" size="450" color="white" frame="true" align="right" spinBox="true" caption="1oxy, resolution 2.4Å" /> '''CRYSTALLOGRAPHIC ANAL...) |
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| - | [[Image:1oxy.gif|left|200px]]<br /><applet load="1oxy" size=" | + | [[Image:1oxy.gif|left|200px]]<br /><applet load="1oxy" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1oxy, resolution 2.4Å" /> | caption="1oxy, resolution 2.4Å" /> | ||
'''CRYSTALLOGRAPHIC ANALYSIS OF OXYGENATED AND DEOXYGENATED STATES OF ARTHROPOD HEMOCYANIN SHOWS UNUSUAL DIFFERENCES'''<br /> | '''CRYSTALLOGRAPHIC ANALYSIS OF OXYGENATED AND DEOXYGENATED STATES OF ARTHROPOD HEMOCYANIN SHOWS UNUSUAL DIFFERENCES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The X-ray structure of an oxygenated hemocyanin molecule, subunit II of | + | 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. |
==About this Structure== | ==About this Structure== | ||
| - | 1OXY is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Limulus_polyphemus Limulus polyphemus] with CU and OXY as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1OXY is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Limulus_polyphemus Limulus polyphemus] with <scene name='pdbligand=CU:'>CU</scene> and <scene name='pdbligand=OXY:'>OXY</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OXY OCA]. |
==Reference== | ==Reference== | ||
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[[Category: oxygen transport]] | [[Category: oxygen transport]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 14:23:01 2008'' |
Revision as of 12:23, 21 February 2008
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CRYSTALLOGRAPHIC ANALYSIS OF OXYGENATED AND DEOXYGENATED STATES OF ARTHROPOD HEMOCYANIN SHOWS UNUSUAL DIFFERENCES
Overview
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.
About this Structure
1OXY is a Single protein structure of sequence from Limulus polyphemus with and as ligands. Full crystallographic information is available from OCA.
Reference
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
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