2W8X

Structure of the tick ion-channel modulator Ra-KLP

2W8X の概要

• エントリーDOI: 10.2210/pdb2w8x/pdb
• 分子名称: ION-CHANNEL MODULATOR RAKLP, GLYCEROL, ACETATE ION, ... (5 entities in total)
• 機能のキーワード: salivary gland, kunitz domains, maxik channel activation, sulphur sad, membrane protein
• 由来する生物種: RHIPICEPHALUS APPENDICULATUS (TICK)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 17058.89

構造登録者

Paesen, G.C.,Siebold, C.,Dallas, M.,Peers, C.,Harlos, K.,Nuttall, P.A.,Nunn, M.A.,Stuart, D.I.,Esnouf, R.M. (登録日: 2009-01-20, 公開日: 2009-05-05, 最終更新日: 2024-11-06)

主引用文献

Paesen, G.C.,Siebold, C.,Dallas, M.L.,Peers, C.,Harlos, K.,Nuttall, P.A.,Nunn, M.A.,Stuart, D.I.,Esnouf, R.M.
An Ion-Channel Modulator from the Saliva of the Brown Ear Tick Has a Highly Modified Kunitz/Bpti Structure.
J.Mol.Biol., 389:734-, 2009

PubMed Abstract: Ra-KLP, a 75 amino acid protein secreted by the salivary gland of the brown ear tick Rhipicephalus appendiculatus has a sequence resembling those of Kunitz/BPTI proteins. We report the detection, purification and characterization of the function of Ra-KLP. In addition, determination of the three-dimensional crystal structure of Ra-KLP at 1.6 A resolution using sulphur single-wavelength anomalous dispersion reveals that much of the loop structure of classical Kunitz domains, including the protruding protease-binding loop, has been replaced by beta-strands. Even more unusually, the N-terminal portion of the polypeptide chain is pinned to the "Kunitz head" by two disulphide bridges not found in classical Kunitz/BPTI proteins. The disulphide bond pattern has been further altered by the loss of the bridge that normally stabilizes the protease-binding loop. Consistent with the conversion of this loop into a beta-strand, Ra-KLP shows no significant anti-protease activity; however, it activates maxiK channels in an in vitro system, suggesting a potential mechanism for regulating host blood supply during feeding.

PubMed: 19394347
DOI: 10.1016/J.JMB.2009.04.045

実験手法

X-RAY DIFFRACTION (1.6 Å)