Microtubule interaction site of the kinesin motor.
Kinesin and myosin are motor proteins that share a common structural core and bind to microtubules and actin filaments, respectively. While the actomyosin interface has been well studied, the location of the microtubule-binding site on kinesin has not been identified. Using alanine-scanning mutagenesis, we have found that microtubule-interacting kinesin residues are located in three loops that cluster in a patch on the motor surface. The critical residues are primarily positively charged, which is consistent with a primarily electrostatic interaction with the negatively charged tubulin molecule. The core of the microtubule-binding interface resides in a highly conserved loop and helix (L12/alpha5) that corresponds topologically to the major actin-binding domain of myosin. Thus, kinesin and myosin have developed distinct polymer-binding domains in a similar region with respect to their common catalytic cores.
Woehlke
G
G
Howard Hughes Medical Institute, Department of Pharmacology, University of California, San Francisco, 94143, USA.
Ruby
A K
AK
Hart
C L
CL
Ly
B
B
Hom-Booher
N
N
Vale
R D
RD
D000251:Adenosine Triphosphatases / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D016547:Kinesins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008870:Microtubules / Q000737:chemistry / Q000201:enzymology*; D016297:Mutagenesis, Site-Directed / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary
D001426:Bacterial Proteins; D000251:Adenosine Triphosphatases; D016547:Kinesins