4lnu
Nucleotide-free kinesin motor domain in complex with tubulin and a DARPinNucleotide-free kinesin motor domain in complex with tubulin and a DARPin
Structural highlights
FunctionW5QC38_SHEEP 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.[ARBA:ARBA00004036][RuleBase:RU000352] Publication Abstract from PubMedKinesin-1 is a dimeric ATP-dependent motor protein that moves towards microtubules (+) ends. This movement is driven by two conformations (docked and undocked) of the two motor domains carboxy-terminal peptides (named neck linkers), in correlation with the nucleotide bound to each motor domain. Despite extensive data on kinesin-1, the structural connection between its nucleotide cycle and movement has remained elusive, mostly because the structure of the critical tubulin-bound apo-kinesin state was unknown. Here we report the 2.2 A structure of this complex. From its comparison with detached kinesin-ADP and tubulin-bound kinesin-ATP, we identify three kinesin motor subdomains that move rigidly along the nucleotide cycle. Our data reveal how these subdomains reorient on binding to tubulin and when ATP binds, leading respectively to ADP release and to neck linker docking. These results establish a framework for understanding the transformation of chemical energy into mechanical work by (+) end-directed kinesins. The structure of apo-kinesin bound to tubulin links the nucleotide cycle to movement.,Cao L, Wang W, Jiang Q, Wang C, Knossow M, Gigant B Nat Commun. 2014 Nov 14;5:5364. doi: 10.1038/ncomms6364. PMID:25395082[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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