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Publication Abstract from PubMed

Kinesin is a motor protein, comprised of two heavy and two light chains that transports cargo along the cytoskeletal microtubule filament network. The heavy chain has a neck domain connecting the ATPase motor head responsible for walking along microtubules, with the stalk and subsequent tail domains that bind cargo. The neck domain consists of a coiled coli homodimer with about five heptad repeats, preceded by a linker region that joins to the ATPase head. Here we report (1)H, (15)N, and (13)C NMR assignments and a solution structure for the kinesin neck domain from rat isoform Kif5c. The calculation of the NMR structure of the homodimer was facilitated by unambiguously assigning sidechain NOEs between heptad a and d positions to interchain contacts, since these positions are too far apart to give sidechain contacts in the monomers. The dimeric coiled coil NMR structure is similar to the previously described X-ray structure, whereas the linker region is disordered in solution but contains a short segment with beta-strand propensity- the beta-linker. Only the coiled coil is protected from solvent exchange, with ∆G values for hydrogen exchange on the order of 4-6 kcal/mol. The high stability of the hydrogen-bonded alpha-helical structure makes it unlikely that unzippering of the coiled coil is involved in kinesin walking. Rather, the linker region serves as a flexible hinge between the kinesin head and neck.

Solution NMR assignments and structure for the dimeric kinesin neck domain.,Seo D, Kammerer RA, Alexandrescu AT Biomol NMR Assign. 2023 Oct 20. doi: 10.1007/s12104-023-10159-x. PMID:37861970^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.