5mlv
From Proteopedia
S. pombe microtubule decorated with Cut7 motor domain in the AMPPNP state
Structural highlights
Function[TBA1_SCHPO] 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_SCHPO] 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. [CUT7_SCHPO] Could be a spindle pole body motor. On transition from G2 to M phase of the cell cycle, the spindle pole body duplicates; the daughter pole bodies seed microtubules which interdigitate to form a short spindle that elongates to span the nucleus at metaphase. Mutations at cut7 block spindle formation. Publication Abstract from PubMedKinesin-5s are microtubule-dependent motors that drive spindle pole separation during mitosis. We used cryo-electron microscopy to determine the 4.5-A resolution structure of the motor domain of the fission yeast kinesin-5 Cut7 bound to fission yeast microtubules and explored the topology of the motor-microtubule interface and the susceptibility of the complex to drug binding. Despite their non-canonical architecture and mechanochemistry, Schizosaccharomyces pombe microtubules were stabilized by epothilone at the taxane binding pocket. The overall Cut7 footprint on the S. pombe microtubule surface is altered compared to mammalian tubulin microtubules because of their different polymer architectures. However, the core motor-microtubule interaction is tightly conserved, reflected in similar Cut7 ATPase activities on each microtubule type. AMPPNP-bound Cut7 adopts a kinesin-conserved ATP-like conformation including cover neck bundle formation. However, the Cut7 ATPase is not blocked by a mammalian-specific kinesin-5 inhibitor, consistent with the non-conserved sequence and structure of its loop5 insertion. Cryo-EM Structure (4.5-A) of Yeast Kinesin-5-Microtubule Complex Reveals a Distinct Binding Footprint and Mechanism of Drug Resistance.,von Loeffelholz O, Pena A, Drummond DR, Cross R, Moores CA J Mol Biol. 2019 Feb 15;431(4):864-872. doi: 10.1016/j.jmb.2019.01.011. Epub 2019, Jan 16. PMID:30659798[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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