The ATPase cycle of the mitotic motor CENP-E.
We have previously shown that the mitotic motor centrosome protein E (CENP-E) is capable of walking for more than 250 steps on its microtubule track without dissociating. We have examined the kinetics of this molecular motor to see if its enzymology explains this remarkable degree of processivity. We find that like the highly processive transport motor kinesin 1, the enzymatic cycle of CENP-E is characterized by rapid ATP binding, multiple enzymatic turnovers per diffusive encounter, and gating of nucleotide binding. These features endow CENP-E with a high duty cycle, a prerequisite for processivity. However, unlike kinesin 1, neck linker docking in CENP-E is slow, occurring at a rate closer to that for Eg5, a mitotic kinesin that takes only 5-10 steps per processive run. These results suggest that like kinesin 1, features outside of the catalytic domain of CENP-E may also play a role in regulating the processive behavior of this motor.
Rosenfeld
Steven S
SS
Department of Biology, Columbia University, New York, New York 10032, USA. sr2327@columbia.edu
van Duffelen
Marilyn
M
Behnke-Parks
William M
WM
Beadle
Christopher
C
Corrreia
John
J
Xing
Jun
J
D000251:Adenosine Triphosphatases / Q000737:chemistry*; D000255:Adenosine Triphosphate / Q000737:chemistry; D000818:Animals; D020134:Catalytic Domain; D002868:Chromosomal Proteins, Non-Histone / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D016547:Kinesins / Q000737:chemistry; D007700:Kinetics; D008870:Microtubules / Q000378:metabolism*; D008938:Mitosis; D009705:Nucleosides / Q000737:chemistry; D009711:Nucleotides / Q000737:chemistry; D011485:Protein Binding; D029867:Xenopus Proteins / Q000737:chemistry; D014982:Xenopus laevis
D002868:Chromosomal Proteins, Non-Histone; C088335:KIF11 protein, Xenopus; D009705:Nucleosides; D009711:Nucleotides; D029867:Xenopus Proteins; C068688:centromere protein E; D000255:Adenosine Triphosphate; D000251:Adenosine Triphosphatases; D016547:Kinesins