ジャーナル: J Virol / 年: 2014 タイトル: Kinetic and structural analysis of coxsackievirus B3 receptor interactions and formation of the A-particle. 著者: Lindsey J Organtini / Alexander M Makhov / James F Conway / Susan Hafenstein / Steven D Carson / 要旨: The coxsackievirus and adenovirus receptor (CAR) has been identified as the cellular receptor for group B coxsackieviruses, including serotype 3 (CVB3). CAR mediates infection by binding to CVB3 and ...The coxsackievirus and adenovirus receptor (CAR) has been identified as the cellular receptor for group B coxsackieviruses, including serotype 3 (CVB3). CAR mediates infection by binding to CVB3 and catalyzing conformational changes in the virus that result in formation of the altered, noninfectious A-particle. Kinetic analyses show that the apparent first-order rate constant for the inactivation of CVB3 by soluble CAR (sCAR) at physiological temperatures varies nonlinearly with sCAR concentration. Cryo-electron microscopy (cryo-EM) reconstruction of the CVB3-CAR complex resulted in a 9.0-Å resolution map that was interpreted with the four available crystal structures of CAR, providing a consensus footprint for the receptor binding site. The analysis of the cryo-EM structure identifies important virus-receptor interactions that are conserved across picornavirus species. These conserved interactions map to variable antigenic sites or structurally conserved regions, suggesting a combination of evolutionary mechanisms for receptor site preservation. The CAR-catalyzed A-particle structure was solved to a 6.6-Å resolution and shows significant rearrangement of internal features and symmetric interactions with the RNA genome. Importance: This report presents new information about receptor use by picornaviruses and highlights the importance of attaining at least an ∼9-Å resolution for the interpretation of cryo-EM ...Importance: This report presents new information about receptor use by picornaviruses and highlights the importance of attaining at least an ∼9-Å resolution for the interpretation of cryo-EM complex maps. The analysis of receptor binding elucidates two complementary mechanisms for preservation of the low-affinity (initial) interaction of the receptor and defines the kinetics of receptor-catalyzed conformational change to the A-particle.
名称: Coxsackievirus B3 A-Particle / 詳細: purified virus and receptor complex in solution / 構成要素数: 1 / オリゴマーの状態: icosahedral virus
分子量
実験値: 7 MDa
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構成要素 #1: ウイルス, Human coxsackievirus B3
ウイルス
名称: Human coxsackievirus B3 / 別称: CVB3 / クラス: VIRION 詳細: Virus was incubated with excess CAR at 4 degrees C then transitioned to 37 degrees C in order to create the A-particle. 中空か: No / エンベロープを持つか: No / 単離: STRAIN
分子量
実験値: 7 MDa
生物種
生物種: Human coxsackievirus B3 (コクサッキーウイルス) 株: CVB3/28
由来(天然)
宿主: Homo sapiens (ヒト) / 宿主のカテゴリ: VERTEBRATES
殻 #1
要素名: VP1-4 / 直径: 300 Å / T番号(三角分割数): 1
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実験情報
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試料調製
試料
試料の状態: 粒子 / 手法: クライオ電子顕微鏡法
試料溶液
試料濃度: 0.1 mg/mL / 緩衝液: 50 mM MES, 100 mM NaCl / pH: 6
支持膜
glow-discharged holey carbon Quantifoil electron microscopy grids
凍結
装置: FEI VITROBOT MARK III / 凍結剤: ETHANE-PROPANE MIXTURE / 温度: 95 K / 湿度: 95 %