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Key residues on microtubule responsible for activation of kinesin ATPase
Author(s) -
Uchimura Seiichi,
Oguchi Yusuke,
Hachikubo You,
Ishiwata Shin'ichi,
Muto Etsuko
Publication year - 2010
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2010.25
Subject(s) - microtubule , tubulin , kinesin , atp hydrolysis , biology , binding site , alanine , adenosine triphosphate , biophysics , atpase , biochemistry , microbiology and biotechnology , nucleotide , plasma protein binding , amino acid , enzyme , gene
Microtubule (MT) binding accelerates the rate of ATP hydrolysis in kinesin. To understand the underlying mechanism, using charged‐to‐alanine mutational analysis, we identified two independent sites in tubulin, which are critical for kinesin motility, namely, a cluster of negatively charged residues spanning the helix 11–12 (H11–12) loop and H12 of α‐tubulin, and the negatively charged residues in H12 of β‐tubulin. Mutation in the α‐tubulin‐binding site results in a deceleration of ATP hydrolysis ( k cat ), whereas mutation in the β‐tubulin‐binding site lowers the affinity for MTs ( K 0.5 MT). The residue E415 in α‐tubulin seems to be important for coupling MT binding and ATPase activation, because the mutation at this site results in a drastic reduction in the overall rate of ATP hydrolysis, largely due to a deceleration in the reaction of ADP release. Our results suggest that kinesin binding at a region containing α‐E415 could transmit a signal to the kinesin nucleotide pocket, triggering its conformational change and leading to the release of ADP.