Feedback of the kinesin-1 neck-linker position on the catalytic site.
Kinesin-1 motor proteins step along microtubules by a mechanism in which the heads cycle through microtubule-bound and unbound states in an interlaced fashion. An important contribution to head-head coordination arises from the action of the neck-linker that docks onto the core motor domain upon ATP binding. We show here that the docked neck-linker not only guides the microtubule-unbound head to the next microtubule binding site but also signals its position to the head to which it is attached. Cross-linking studies on mutated kinesin constructs reveal that residues at the interface motor core/docked neck-linker, among them most importantly a conserved tyrosine, are involved in this feedback. The primary effect of the docked neck-linker is a reduced microtubule binding affinity in the ADP state.
Hahlen
Katrin
K
Institute for Cell Biology, Ludwig-Maximilians University, Schillerstrasse 42, 80336 München, Germany.
Ebbing
Bettina
B
Reinders
Jörg
J
Mergler
Judith
J
Sickmann
Albert
A
Woehlke
Guenther
G