2PY2

Structure of Herring Type II Antifreeze Protein

2PY2 の概要

• エントリーDOI: 10.2210/pdb2py2/pdb
• 分子名称: Antifreeze protein type II, CALCIUM ION (3 entities in total)
• 機能のキーワード: type ii antifreeze protein, antifreeze protein
• 由来する生物種: Clupea harengus (Atlantic herring)
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 92990.82

構造登録者

Liu, Y.,Li, Z.,Lin, Q.,Seetharaman, J.,Sivaraman, J.,Hew, C.-L. (登録日: 2007-05-15, 公開日: 2007-06-26, 最終更新日: 2024-11-20)

主引用文献

Liu, Y.,Li, Z.,Lin, Q.,Kosinski, J.,Seetharaman, J.,Bujnicki, J.M.,Sivaraman, J.,Hew, C.L.
Structure and Evolutionary Origin of Ca-Dependent Herring Type II Antifreeze Protein.
PLoS ONE, 2:e548-e548, 2007

PubMed Abstract: 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.

PubMed: 17579720
DOI: 10.1371/journal.pone.0000548

実験手法

X-RAY DIFFRACTION (1.7 Å)