ジャーナル: J Cell Biol / 年: 2010 タイトル: Template-free 13-protofilament microtubule-MAP assembly visualized at 8 A resolution. 著者: Franck J Fourniol / Charles V Sindelar / Béatrice Amigues / Daniel K Clare / Geraint Thomas / Mylène Perderiset / Fiona Francis / Anne Houdusse / Carolyn A Moores / 要旨: Microtubule-associated proteins (MAPs) are essential for regulating and organizing cellular microtubules (MTs). However, our mechanistic understanding of MAP function is limited by a lack of detailed ...Microtubule-associated proteins (MAPs) are essential for regulating and organizing cellular microtubules (MTs). However, our mechanistic understanding of MAP function is limited by a lack of detailed structural information. Using cryo-electron microscopy and single particle algorithms, we solved the 8 Å structure of doublecortin (DCX)-stabilized MTs. Because of DCX's unusual ability to specifically nucleate and stabilize 13-protofilament MTs, our reconstruction provides unprecedented insight into the structure of MTs with an in vivo architecture, and in the absence of a stabilizing drug. DCX specifically recognizes the corner of four tubulin dimers, a binding mode ideally suited to stabilizing both lateral and longitudinal lattice contacts. A striking consequence of this is that DCX does not bind the MT seam. DCX binding on the MT surface indirectly stabilizes conserved tubulin-tubulin lateral contacts in the MT lumen, operating independently of the nucleotide bound to tubulin. DCX's exquisite binding selectivity uncovers important insights into regulation of cellular MTs.
アルゴリズム: OTHER / 解像度のタイプ: BY AUTHOR / 解像度: 8.2 Å / 解像度の算出法: FSC 0.5 CUT-OFF / ソフトウェア - 名称: SPIDER, FREALIGN 詳細: Approximately 168,000 asymmetric units were averaged together in the final map
Protocol: Rigid body. 4 tubulin monomers were fitted separately in 3D map, which was zoned around the subunits, and multiple subunit fitting was refined in Flex-EM
精密化
空間: REAL / プロトコル: RIGID BODY FIT / 当てはまり具合の基準: Cross-correlation
得られたモデル
PDB-2xrp: Human Doublecortin N-DC Repeat (1MJD) and Mammalian Tubulin (1JFF and 3HKE) Docked into the 8-Angstrom Cryo-EM Map of Doublecortin- Stabilised Microtubules
PDBEntryID_givenInChain. Protocol: Rigid body. 4 tubulin monomers were fitted separately in 3D map, which was zoned around the subunits, and multiple subunit fitting was refined in Flex-EM
精密化
空間: REAL / プロトコル: RIGID BODY FIT / 当てはまり具合の基準: Cross-correlation
得られたモデル
PDB-2xrp: Human Doublecortin N-DC Repeat (1MJD) and Mammalian Tubulin (1JFF and 3HKE) Docked into the 8-Angstrom Cryo-EM Map of Doublecortin- Stabilised Microtubules