1msi
From Proteopedia
(New page: 200px<br /><applet load="1msi" size="450" color="white" frame="true" align="right" spinBox="true" caption="1msi, resolution 1.25Å" /> '''STRUCTURE OF ANTIFRE...) |
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| - | [[Image:1msi.gif|left|200px]]<br /><applet load="1msi" size=" | + | [[Image:1msi.gif|left|200px]]<br /><applet load="1msi" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1msi, resolution 1.25Å" /> | caption="1msi, resolution 1.25Å" /> | ||
'''STRUCTURE OF ANTIFREEZE GLYCOPROTEIN QAE(HPLC 12)'''<br /> | '''STRUCTURE OF ANTIFREEZE GLYCOPROTEIN QAE(HPLC 12)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Antifreeze proteins (AFPs) have the unique ability to adsorb to ice and | + | Antifreeze proteins (AFPs) have the unique ability to adsorb to ice and inhibit its growth. Many organisms ranging from fish to bacteria use AFPs to retard freezing or lessen the damage incurred upon freezing and thawing. The ice-binding mechanism of the long linear alpha-helical type I AFPs has been attributed to their regularly spaced polar residues matching the ice lattice along a pyramidal plane. In contrast, it is not known how globular antifreeze proteins such as type III AFP that lack repeating ice-binding residues bind to ice. Here we report the 1.25 A crystal structure of recombinant type III AFP (QAE isoform) from eel pout (Macrozoarces americanus), which reveals a remarkably flat amphipathic ice-binding site where five hydrogen-bonding atoms match two ranks of oxygens on the [1010] ice prism plane in the <0001> direction, giving high ice-binding affinity and specificity. This binding site, substantiated by the structures and properties of several ice-binding site mutants, suggests that the AFP occupies a niche in the ice surface in which it covers the basal plane while binding to the prism face. |
==About this Structure== | ==About this Structure== | ||
| - | 1MSI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Macrozoarces_americanus Macrozoarces americanus]. Full crystallographic information is available from [http:// | + | 1MSI is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Macrozoarces_americanus Macrozoarces americanus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1MSI OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Single protein]] | [[Category: Single protein]] | ||
[[Category: Chao, H.]] | [[Category: Chao, H.]] | ||
| - | [[Category: Davies, P | + | [[Category: Davies, P L.]] |
| - | [[Category: Deluca, C | + | [[Category: Deluca, C I.]] |
[[Category: Jia, Z.]] | [[Category: Jia, Z.]] | ||
[[Category: antifreeze protein]] | [[Category: antifreeze protein]] | ||
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[[Category: thermal hysteresis]] | [[Category: thermal hysteresis]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:58:35 2008'' |
Revision as of 11:58, 21 February 2008
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STRUCTURE OF ANTIFREEZE GLYCOPROTEIN QAE(HPLC 12)
Overview
Antifreeze proteins (AFPs) have the unique ability to adsorb to ice and inhibit its growth. Many organisms ranging from fish to bacteria use AFPs to retard freezing or lessen the damage incurred upon freezing and thawing. The ice-binding mechanism of the long linear alpha-helical type I AFPs has been attributed to their regularly spaced polar residues matching the ice lattice along a pyramidal plane. In contrast, it is not known how globular antifreeze proteins such as type III AFP that lack repeating ice-binding residues bind to ice. Here we report the 1.25 A crystal structure of recombinant type III AFP (QAE isoform) from eel pout (Macrozoarces americanus), which reveals a remarkably flat amphipathic ice-binding site where five hydrogen-bonding atoms match two ranks of oxygens on the [1010] ice prism plane in the <0001> direction, giving high ice-binding affinity and specificity. This binding site, substantiated by the structures and properties of several ice-binding site mutants, suggests that the AFP occupies a niche in the ice surface in which it covers the basal plane while binding to the prism face.
About this Structure
1MSI is a Single protein structure of sequence from Macrozoarces americanus. Full crystallographic information is available from OCA.
Reference
Structural basis for the binding of a globular antifreeze protein to ice., Jia Z, DeLuca CI, Chao H, Davies PL, Nature. 1996 Nov 21;384(6606):285-8. PMID:8918883
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