4MOA

Crystal structure of CRY4BA-R203Q TOXIN

4MOA の概要

• エントリーDOI: 10.2210/pdb4moa/pdb
• 分子名称: Pesticidal crystal protein cry4Ba (2 entities in total)
• 機能のキーワード: toxin, pesticidal protein
• 由来する生物種: Bacillus thuringiensis serovar israelensis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 67674.95

構造登録者

Thamwiriyasati, N.,Angsuthanasombat, C.,Chen, C.-J. (登録日: 2013-09-11, 公開日: 2014-12-10, 最終更新日: 2023-11-08)

主引用文献

Sriwimol, W.,Aroonkesorn, A.,Sakdee, S.,Kanchanawarin, C.,Uchihashi, T.,Ando, T.,Angsuthanasombat, C.
Potential Prepore Trimer Formation by the Bacillus thuringiensis Mosquito-specific Toxin: MOLECULAR INSIGHTS INTO A CRITICAL PREREQUISITE OF MEMBRANE-BOUND MONOMERS
J.Biol.Chem., 290:20793-20803, 2015

PubMed Abstract: The insecticidal feature of the three-domain Cry δ-endotoxins from Bacillus thuringiensis is generally attributed to their capability to form oligomeric pores, causing lysis of target larval midgut cells. However, the molecular description of their oligomerization process has not been clearly defined. Here a stable prepore of the 65-kDa trypsin-activated Cry4Ba mosquito-specific toxin was established through membrane-mimetic environments by forming an ∼200-kDa octyl-β-D-glucoside micelle-induced trimer. The SDS-resistant trimer caused cytolysis to Sf9 insect cells expressing Aedes-mALP (a Cry4Ba receptor) and was more effective than a toxin monomer in membrane perturbation of calcein-loaded liposomes. A three-dimensional model of toxin trimer obtained by negative-stain EM in combination with single-particle reconstruction at ∼5 nm resolution showed a propeller-shaped structure with 3-fold symmetry. Fitting the three-dimensional reconstructed EM map with a 100-ns molecular dynamics-simulated Cry4Ba structure interacting with an octyl-β-D-glucoside micelle showed relative positioning of individual domains in the context of the trimeric complex with a major protrusion from the pore-forming domain. Moreover, high-speed atomic force microscopy imaging at nanometer resolution and a subsecond frame rate demonstrated conformational transitions from a propeller-like to a globularly shaped trimer upon lipid membrane interactions, implying prepore-to-pore conversion. Real-time trimeric arrangement of monomers associated with L-α-dimyristoylphosphatidylcholine/3-[(3-cholamidopropyl)dimethylammonio]-2-hydroxy-1-propanesulfonic acid bicelle membranes was also envisaged by successive high-speed atomic force microscopy imaging, depicting interactions among three individual subunits toward trimer formation. Together, our data provide the first pivotal insights into the structural requirement of membrane-induced conformational changes of Cry4Ba toxin monomers for the molecular assembly of a prepore trimer capable of inserting into target membranes to generate a lytic pore.

PubMed: 26112409
DOI: 10.1074/jbc.M114.627554

実験手法

X-RAY DIFFRACTION (2 Å)