title: High-resolution microtubule structures reveal the structural transitions in αβ-tubulin upon GTP hydrolysis.
abstract: 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.
authors.affiliation: Biophysics Graduate Program, University of California, Berkeley, Berkeley, CA 94720, USA.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Alushin
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA.
authors.forename: Gabriel C
authors.initials: GC
authors.lastname: Lander
authors.affiliation: Howard Hughes Medical Institute, Department of Biochemistry, University of Washington, Seattle, WA 98105, USA.
authors.forename: Elizabeth H
authors.initials: EH
authors.lastname: Kellogg
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: Howard Hughes Medical Institute, Department of Biochemistry, University of Washington, Seattle, WA 98105, USA.
authors.forename: David
authors.initials: D
authors.lastname: Baker
authors.affiliation: Life Sciences Division, Lawrence Berkeley National Lab, Berkeley, CA 94720, USA; Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720, USA. Electronic address: enogales@lbl.gov.
authors.forename: Eva
authors.initials: E
authors.lastname: Nogales
mesh_terms: D000818:Animals; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D006160:Guanosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D008870:Microtubules / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D008958:Models, Molecular; D017239:Paclitaxel / Q000378:metabolism; D011487:Protein Conformation; D014404:Tubulin / Q000737:chemistry* / Q000378:metabolism
chemical_list: D014404:Tubulin; C004805:5'-guanylylmethylenebisphosphonate; D006160:Guanosine Triphosphate; D017239:Paclitaxel