7a40
Nucleotide-free OSM-3 kinesin motor domainNucleotide-free OSM-3 kinesin motor domain
Structural highlights
FunctionOSM3_CAEEL Kinesin motor protein which is required for the anterograde intraflagellar transport (IFT) along the middle segment of the sensory neuron cilia together with the kinesin II motor complex (composed of klp-11, klp-20 and kap-1) and on its own, is required for IFT along the distal segment (PubMed:17000880, PubMed:17420466). In addition, regulates the length of cilia (PubMed:17420466). May have a role during neurogenesis and axonal transport (PubMed:7714894, PubMed:7690265).[1] [2] [3] [4] Publication Abstract from PubMedMotile kinesins are motor proteins that translocate along microtubules as they hydrolyze ATP. They share a conserved motor domain which harbors both ATPase and microtubule-binding activities. An ATP hydrolysis mechanism involving two water molecules has been proposed based on the structure of the kinesin-5 Eg5 bound to an ATP analog. Whether this mechanism is general in the kinesin superfamily remains uncertain. Here, we present structural snapshots of the motor domain of OSM-3 along its nucleotide cycle. OSM-3 belongs to the homodimeric kinesin-2 subfamily and is the Caenorhabditis elegans homologue of human KIF17. OSM-3 bound to ADP or devoid of a nucleotide shows features of ADP-kinesins with a docked neck linker. When bound to an ATP analog, OSM-3 adopts a conformation similar to those of several ATP-like kinesins, either isolated or bound to tubulin. Moreover, the OSM-3 nucleotide-binding site is virtually identical to that of ATP-like Eg5, demonstrating a shared ATPase mechanism. Therefore, our data extend to kinesin-2 the two-water ATP hydrolysis mechanism and further suggest that it is universal within the kinesin superfamily. PROTEIN DATABASE ENTRIES: 7A3Z, 7A40, 7A5E. Structural snapshots of the kinesin-2 OSM-3 along its nucleotide cycle: implications for the ATP hydrolysis mechanism.,Varela PF, Chenon M, Velours C, Verhey KJ, Menetrey J, Gigant B FEBS Open Bio. 2021 Mar;11(3):564-577. doi: 10.1002/2211-5463.13101. Epub 2021 , Feb 28. PMID:33513284[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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