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.
Naber
Nariman
N
Department of Biochemistry, University of California, San Francisco, CA 94143, USA. naber@itsa.ucsf.edu
Minehardt
Todd J
TJ
Rice
Sarah
S
Chen
Xiaoru
X
Grammer
Jean
J
Matuska
Marija
M
Vale
Ronald D
RD
Kollman
Peter A
PA
Car
Roberto
R
Yount
Ralph G
RG
Cooke
Roger
R
Pate
Edward
E
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