ジャーナル: Cell / 年: 2014 タイトル: High-resolution microtubule structures reveal the structural transitions in αβ-tubulin upon GTP hydrolysis. 著者: Gregory M Alushin / Gabriel C Lander / Elizabeth H Kellogg / Rui Zhang / David Baker / Eva Nogales / 要旨: Dynamic instability, the stochastic switching between growth and shrinkage, is essential for microtubule function. This behavior is driven by GTP hydrolysis in the microtubule lattice and is ...Dynamic instability, the stochastic switching between growth and shrinkage, is essential for microtubule function. This behavior is driven by GTP hydrolysis in the microtubule lattice and is inhibited by anticancer agents like Taxol. We provide insight into the mechanism of dynamic instability, based on high-resolution cryo-EM structures (4.7-5.6 Å) of dynamic microtubules and microtubules stabilized by GMPCPP or Taxol. We infer that hydrolysis leads to a compaction around the E-site nucleotide at longitudinal interfaces, as well as movement of the α-tubulin intermediate domain and H7 helix. Displacement of the C-terminal helices in both α- and β-tubulin subunits suggests an effect on interactions with binding partners that contact this region. Taxol inhibits most of these conformational changes, allosterically inducing a GMPCPP-like state. Lateral interactions are similar in all conditions we examined, suggesting that microtubule lattice stability is primarily modulated at longitudinal interfaces.
Initial alignments performed with EMAN2/SPARX, including refinement of helical parameters with the IHRSR programs of Egelman. Final alignment and reconstruction performed with FREALIGN.
CTF補正
詳細: ctftilt
最終 再構成
想定した対称性 - らせんパラメータ - Δz: 8.96 Å 想定した対称性 - らせんパラメータ - ΔΦ: 25.75 ° 想定した対称性 - らせんパラメータ - 軸対称性: C1 (非対称) アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 5.5 Å / 解像度の算出法: OTHER / ソフトウェア - 名称: FREALIGN / 使用した粒子像数: 24357