Key residues on microtubule responsible for activation of kinesin ATPase.
EMBO J
; 29(7): 1167-75, 2010 Apr 07.
Article
em En
| MEDLINE
| ID: mdl-20224548
ABSTRACT
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 alpha-tubulin, and the negatively charged residues in H12 of beta-tubulin. Mutation in the alpha-tubulin-binding site results in a deceleration of ATP hydrolysis (k(cat)), whereas mutation in the beta-tubulin-binding site lowers the affinity for MTs (K(0.5)MT). The residue E415 in alpha-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 alpha-E415 could transmit a signal to the kinesin nucleotide pocket, triggering its conformational change and leading to the release of ADP.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Saccharomyces cerevisiae
/
Tubulina (Proteína)
/
Cinesinas
/
Proteínas de Saccharomyces cerevisiae
/
Microtúbulos
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article