Kinesin's second step.
We have identified dimeric kinesin mutants that become stalled on the microtubule after one ATP turnover, unable to bind and hydrolyze ATP at their second site. We have used these mutants to determine the regulatory signal that allows ATP to bind to the forward head, such that processive movement can continue. The results show that phosphate release occurs from the rearward head before detachment, and detachment triggers active-site accessibility for ATP binding at the forward head. This mechanism, in which the rearward head controls the behavior of the forward head, may be conserved among processive motors.
Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Lisa M
LM
Klumpp
Andreas
A
Hoenger
Susan P
SP
Gilbert
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D019281:Dimerization; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism; D006801:Humans; D066298:In Vitro Techniques; D016547:Kinesins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D046911:Macromolecular Substances; D008870:Microtubules / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D020409:Molecular Motor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016297:Mutagenesis, Site-Directed; D051381:Rats
D029721:Drosophila Proteins; D046911:Macromolecular Substances; D020409:Molecular Motor Proteins; D000255:Adenosine Triphosphate; D016547:Kinesins