5XQU

Crystal structure of Notched-fin eelpout type III antifreeze protein A20I mutant (NFE6, AFP), P212121 form

5XQU の概要

• エントリーDOI: 10.2210/pdb5xqu/pdb
• 分子名称: Ice-structuring protein (2 entities in total)
• 機能のキーワード: antifreeze protein
• 由来する生物種: Zoarces elongatus
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 7048.37

構造登録者

Adachi, M.,Shimizu, R.,Shibazaki, C.,Kondo, H.,Tsuda, S. (登録日: 2017-06-07, 公開日: 2018-05-16, 最終更新日: 2023-11-22)

主引用文献

Mahatabuddin, S.,Fukami, D.,Arai, T.,Nishimiya, Y.,Shimizu, R.,Shibazaki, C.,Kondo, H.,Adachi, M.,Tsuda, S.
Polypentagonal ice-like water networks emerge solely in an activity-improved variant of ice-binding protein
Proc. Natl. Acad. Sci. U.S.A., 115:5456-5461, 2018

PubMed Abstract: Polypentagonal water networks were recently observed in a protein capable of binding to ice crystals, or ice-binding protein (IBP). To examine such water networks and clarify their role in ice-binding, we determined X-ray crystal structures of a 65-residue defective isoform of a -derived IBP (wild type, WT) and its five single mutants (A20L, A20G, A20T, A20V, and A20I). Polypentagonal water networks composed of ∼50 semiclathrate waters were observed solely on the strongest A20I mutant, which appeared to include a tetrahedral water cluster exhibiting a perfect position match to the [Formula: see text] first prism plane of a single ice crystal. Inclusion of another symmetrical water cluster in the polypentagonal network showed a perfect complementarity to the waters constructing the [Formula: see text] pyramidal ice plane. The order of ice-binding strength was A20L < A20G < WT < A20T < A20V < A20I, where the top three mutants capable of binding to the first prism and the pyramidal ice planes commonly contained a bifurcated γ-CH group. These results suggest that a fine-tuning of the surface of -derived IBP assisted by a side-chain group regulates the holding property of its polypentagonal water network, the function of which is to freeze the host protein to specific ice planes.

PubMed: 29735675
DOI: 10.1073/pnas.1800635115

実験手法

X-RAY DIFFRACTION (1 Å)