Closing of the nucleotide pocket of kinesin-family motors upon binding to microtubules.
We have used adenosine diphosphate analogs containing electron paramagnetic resonance (EPR) spin moieties and EPR spectroscopy to show that the nucleotide-binding site of kinesin-family motors closes when the motor.diphosphate complex binds to microtubules. Structural analyses demonstrate that a domain movement in the switch 1 region at the nucleotide site, homologous to domain movements in the switch 1 region in the G proteins [heterotrimeric guanine nucleotide-binding proteins], explains the EPR data. The switch movement primes the motor both for the free energy-yielding nucleotide hydrolysis reaction and for subsequent conformational changes that are crucial for the generation of force and directed motion along the microtubule.
Department of Biochemistry, University of California, San Francisco, CA 94143, USA. naber@itsa.ucsf.edu
Nariman
N
Naber
Todd J
TJ
Minehardt
Sarah
S
Rice
Xiaoru
X
Chen
Jean
J
Grammer
Marija
M
Matuska
Ronald D
RD
Vale
Peter A
PA
Kollman
Roberto
R
Car
Ralph G
RG
Yount
Roger
R
Cooke
Edward
E
Pate
D000227:Adenine Nucleotides / Q000378:metabolism*; D000244:Adenosine Diphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D001665:Binding Sites; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D004578:Electron Spin Resonance Spectroscopy; D006801:Humans; D006860:Hydrogen Bonding; D006868:Hydrolysis; D016547:Kinesins / Q000737:chemistry* / Q000378:metabolism*; D008870:Microtubules / Q000378:metabolism*; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000378:metabolism*; D015335:Molecular Probes / Q000378:metabolism; D011487:Protein Conformation; D013113:Spin Labels
D000227:Adenine Nucleotides; D029721:Drosophila Proteins; D020409:Molecular Motor Proteins; D015335:Molecular Probes; D013113:Spin Labels; C066696:ncd protein, Drosophila; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D016547:Kinesins