The Determinants That Govern Microtubule Assembly from the Atomic Structure of GTP-Tubulin.
Nawrotek, A., Knossow, M., Gigant, B.(2011) J Mol Biol 412: 35-42
- PubMed: 21787788 
- DOI: https://doi.org/10.1016/j.jmb.2011.07.029
- Primary Citation of Related Structures:  
3RYC, 3RYF, 3RYH, 3RYI - PubMed Abstract: 
Tubulin alternates between a soluble curved structure and a microtubule straight conformation. GTP binding to αβ-tubulin is required for microtubule assembly, but whether this triggers conversion into a straighter structure is still debated. This is due, at least in part, to the lack of structural data for GTP-tubulin before assembly. Here, we report atomic-resolution crystal structures of soluble tubulin in the GDP and GTP nucleotide states in a complex with a stathmin-like domain. The structures differ locally in the neighborhood of the nucleotide. A loop movement in GTP-bound tubulin favors its recruitment to the ends of growing microtubules and facilitates its curved-to-straight transition, but this conversion has not proceeded yet. The data therefore argue for the conformational change toward the straight structure occurring as microtubule-specific contacts are established. They also suggest a model for the way the tubulin structure is modified in relation to microtubule assembly.
Organizational Affiliation: 
Laboratoire d'Enzymologie et Biochimie Structurales (LEBS), Centre de Recherche de Gif, CNRS, Bat. 34, 1, avenue de la Terrasse, 91198 Gif sur Yvette, France.