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Plasmodium falciparum kinesin-5 motor domain without nucleotide, complexed with 14 protofilament microtubule.Plasmodium falciparum kinesin-5 motor domain without nucleotide, complexed with 14 protofilament microtubule.
Structural highlights
FunctionTBA1B_PIG 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 PubMedPlasmodium parasites cause malaria and are responsible annually for hundreds of thousands of deaths. Kinesins are a superfamily of microtubule-dependent ATPases that play important roles in the parasite replicative machinery, which is a potential target for antiparasite drugs. Kinesin-5, a molecular motor that cross-links microtubules, is an established antimitotic target in other disease contexts, but its mechanism in Plasmodium falciparum is unclear. Here, we characterized P. falciparum kinesin-5 (PfK5) using cryo-EM to determine the motor's nucleotide-dependent microtubule-bound structure and introduced 3D classification of individual motors into our microtubule image processing pipeline to maximize our structural insights. Despite sequence divergence in PfK5, the motor exhibits classical kinesin mechanochemistry, including ATP-induced subdomain rearrangement and cover neck bundle formation, consistent with its plus-ended directed motility. We also observed that an insertion in loop5 of the PfK5 motor domain creates a different environment in the well-characterized human kinesin-5 drug-binding site. Our data reveal the possibility for selective inhibition of PfK5 and can be used to inform future exploration of Plasmodium kinesins as antiparasite targets. Cryo-EM structure of a microtubule-bound parasite kinesin motor and implications for its mechanism and inhibition.,Cook AD, Roberts AJ, Atherton J, Tewari R, Topf M, Moores CA J Biol Chem. 2021 Nov;297(5):101063. doi: 10.1016/j.jbc.2021.101063. Epub 2021 , Aug 8. PMID:34375637[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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