5w3f | pdb_00005w3f
Yeast tubulin polymerized with GTP in vitro
Structural highlights
Function[TBA1_YEAST] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. [TBB_YEAST] Tubulin is the major constituent of microtubules. It binds two moles of GTP, one at an exchangeable site on the beta chain and one at a non-exchangeable site on the alpha chain. Publication Abstract from PubMedMicrotubules are polymers of alphabeta-tubulin heterodimers essential for all eukaryotes. Despite sequence conservation, there are significant structural differences between microtubules assembled in vitro from mammalian or budding yeast tubulin. Yeast MTs were not observed to undergo compaction at the interdimer interface as seen for mammalian microtubules upon GTP hydrolysis. Lack of compaction might reflect slower GTP hydrolysis or a different degree of allosteric coupling in the lattice. The microtubule plus end-tracking protein Bim1 binds yeast microtubules both between alphabeta-tubulin heterodimers, as seen for other organisms, and within tubulin dimers, but binds mammalian tubulin only at interdimer contacts. At the concentrations used in cryo-electron microscopy, Bim1 causes the compaction of yeast microtubules and induces their rapid disassembly. Our studies demonstrate structural differences between yeast and mammalian microtubules that likely underlie their differing polymerization dynamics. These differences may reflect adaptations to the demands of different cell size or range of physiological growth temperatures. Structural differences between yeast and mammalian microtubules revealed by cryo-EM.,Howes SC, Geyer EA, LaFrance B, Zhang R, Kellogg EH, Westermann S, Rice LM, Nogales E J Cell Biol. 2017 Sep 4;216(9):2669-2677. doi: 10.1083/jcb.201612195. Epub 2017, Jun 26. PMID:28652389[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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