2py2
Structure of Herring Type II Antifreeze Protein
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OverviewOverview
In order to survive under extremely cold environments, many organisms, produce antifreeze proteins (AFPs). AFPs inhibit the growth of ice, crystals and protect organisms from freezing damage. Fish AFPs can be, classified into five distinct types based on their structures. Here we, report the structure of herring AFP (hAFP), a Ca(2+)-dependent fish type, II AFP. It exhibits a fold similar to the C-type (Ca(2+)-dependent), lectins with unique ice-binding features. The 1.7 A crystal structure of, hAFP with bound Ca(2+) and site-directed mutagenesis reveal an ice-binding, site consisting of Thr96, Thr98 and Ca(2+)-coordinating residues Asp94 and, Glu99, which initiate hAFP adsorption onto the [10-10] prism plane of the, ice lattice. The hAFP-ice interaction is further strengthened by the bound, Ca(2+) through the coordination with a water molecule of the ice lattice., This Ca(2+)-coordinated ice-binding mechanism is distinct from previously, proposed mechanisms for other AFPs. However, phylogenetic analysis, suggests that all type II AFPs evolved from the common ancestor and, developed different ice-binding modes. We clarify the evolutionary, relationship of type II AFPs to sugar-binding lectins.
About this StructureAbout this Structure
2PY2 is a Single protein structure of sequence from Clupea harengus with as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Structure and Evolutionary Origin of Ca-Dependent Herring Type II Antifreeze Protein., Liu Y, Li Z, Lin Q, Kosinski J, Seetharaman J, Bujnicki JM, Sivaraman J, Hew CL, PLoS ONE. 2007 Jun 20;2:e548. PMID:17579720
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