ジャーナル: EMBO J / 年: 2015 タイトル: X-ray and Cryo-EM structures reveal mutual conformational changes of Kinesin and GTP-state microtubules upon binding. 著者: Manatsu Morikawa / Hiroaki Yajima / Ryo Nitta / Shigeyuki Inoue / Toshihiko Ogura / Chikara Sato / Nobutaka Hirokawa / 要旨: The molecular motor kinesin moves along microtubules using energy from ATP hydrolysis in an initial step coupled with ADP release. In neurons, kinesin-1/KIF5C preferentially binds to the GTP-state ...The molecular motor kinesin moves along microtubules using energy from ATP hydrolysis in an initial step coupled with ADP release. In neurons, kinesin-1/KIF5C preferentially binds to the GTP-state microtubules over GDP-state microtubules to selectively enter an axon among many processes; however, because the atomic structure of nucleotide-free KIF5C is unavailable, its molecular mechanism remains unresolved. Here, the crystal structure of nucleotide-free KIF5C and the cryo-electron microscopic structure of nucleotide-free KIF5C complexed with the GTP-state microtubule are presented. The structures illustrate mutual conformational changes induced by interaction between the GTP-state microtubule and KIF5C. KIF5C acquires the 'rigor conformation', where mobile switches I and II are stabilized through L11 and the initial portion of the neck-linker, facilitating effective ADP release and the weak-to-strong transition of KIF5C microtubule affinity. Conformational changes to tubulin strengthen the longitudinal contacts of the GTP-state microtubule in a similar manner to GDP-taxol microtubules. These results and functional analyses provide the molecular mechanism of the preferential binding of KIF5C to GTP-state microtubules.
解像度: 2.86→20 Å / Cor.coef. Fo:Fc: 0.94 / Cor.coef. Fo:Fc free: 0.909 / WRfactor Rfree: 0.324 / WRfactor Rwork: 0.254 / SU B: 0 / SU ML: 0 / 交差検証法: THROUGHOUT / σ(F): 0 / ESU R: 2.845 / ESU R Free: 0.433 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD 詳細: HYDROGENS HAVE BEEN USED IF PRESENT IN THE INPUT U VALUES: REFINED INDIVIDUALLY
Rfactor
反射数
%反射
Selection details
Rfree
0.2993
1096
5.1 %
RANDOM
Rwork
0.2373
-
-
-
obs
0.2405
21376
99.57 %
-
all
-
21469
-
-
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.2 Å / 溶媒モデル: MASK