3MHZ

1.7A structure of 2-fluorohistidine labeled Protective Antigen

3MHZ の概要

• エントリーDOI: 10.2210/pdb3mhz/pdb
• 分子名称: Protective antigen, CALCIUM ION, TETRAETHYLENE GLYCOL, ... (4 entities in total)
• 機能のキーワード: anthrax, toxin, 2-fluorohistidine, pore, histidine, receptor, hydrogen bonding
• 由来する生物種: Bacillus anthracis (anthrax,anthrax bacterium)
• 細胞内の位置: Secreted, extracellular space: P13423
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 83223.12

構造登録者

Lovell, S.,Battaile, K.P.,Wimalasena, D.S.,Janowiak, B.E.,Miyagi, M.,Sun, J.,Hajduch, J.,Pooput, C.,Kirk, K.L.,Bann, J.G. (登録日: 2010-04-09, 公開日: 2010-08-11, 最終更新日: 2024-11-27)

主引用文献

Wimalasena, D.S.,Janowiak, B.E.,Lovell, S.,Miyagi, M.,Sun, J.,Zhou, H.,Hajduch, J.,Pooput, C.,Kirk, K.L.,Battaile, K.P.,Bann, J.G.
Evidence that histidine protonation of receptor-bound anthrax protective antigen is a trigger for pore formation.
Biochemistry, 49:6973-6983, 2010

PubMed Abstract: The protective antigen (PA) component of the anthrax toxin forms pores within the low pH environment of host endosomes through mechanisms that are poorly understood. It has been proposed that pore formation is dependent on histidine protonation. In previous work, we biosynthetically incorporated 2-fluorohistidine (2-FHis), an isosteric analogue of histidine with a significantly reduced pK(a) ( approximately 1), into PA and showed that the pH-dependent conversion from the soluble prepore to a pore was unchanged. However, we also observed that 2-FHisPA was nonfunctional in the ability to mediate cytotoxicity of CHO-K1 cells by LF(N)-DTA and was defective in translocation through planar lipid bilayers. Here, we show that the defect in cytotoxicity is due to both a defect in translocation and, when bound to the host cellular receptor, an inability to undergo low pH-induced pore formation. Combining X-ray crystallography with hydrogen-deuterium (H-D) exchange mass spectrometry, our studies lead to a model in which hydrogen bonds to the histidine ring are strengthened by receptor binding. The combination of both fluorination and receptor binding is sufficient to block low pH-induced pore formation.

PubMed: 20672855
DOI: 10.1021/bi100647z

実験手法

X-RAY DIFFRACTION (1.7 Å)