What kinesin does at roadblocks: the coordination mechanism for molecular walking.

Crevel, Isabelle M‐TC and Nyitrai, Miklos and Alonso, Maria C. and Weiss, Stefan and Geeves, Michael A. and Cross, Robert A. (2004) What kinesin does at roadblocks: the coordination mechanism for molecular walking. EMBO Journal, 23 (1). pp. 23-32. (Access to this publication is restricted)

PDF
Restricted to Registered users only
Contact us about this Publication Download (309kB)
[img]
Official URL
http://dx.doi.org/10.1038/sj.emboj.7600042

Abstract

Competing models for the coordination of processive stepping in kinesin can be tested by introducing a roadblock to prevent lead head attachment. We used T93N, an irreversibly binding mutant monomer, as a roadblock, and measured the rates of nucleotide-induced detachment of kinesin monomers or dimers with and without the T93N roadblock using microflash photolysis combined with stopped flow. Control nucleotide-induced monomer (rK340) unbinding was 73.6 s(-1) for ATP and 40.5 s(-1) for ADP. Control ADP-induced dimer (rK430) unbinding was 18.6 s(-1). Added 20 mM Pi slowed both monomer and dimer unbinding. With the roadblock in place, lead head attachment of dimers is prevented and ATP-induced trail head unbinding was then 42 s(-1). This is less than two-fold slower than the stepping rate of unimpeded rK430 dimers (50-70 s(-1)), indicating that during walking, lead head attachment induces at most only a slight (less than two-fold) acceleration of trail head detachment. As we discuss, this implies a coordination model having very fast (>2000 s(-1)) ATP-induced attachment of the lead head, followed by slower, strain-sensitive ADP release from the lead head.

Item Type: Article
Subjects: Q Science
Divisions: Faculties > Science Technology and Medical Studies > School of Biosciences > Protein Science Group
Depositing User: Sue Davies
Date Deposited: 19 Dec 2007 17:46
Last Modified: 20 May 2014 15:57
Resource URI: http://kar.kent.ac.uk/id/eprint/26 (The current URI for this page, for reference purposes)
  • Depositors only (login required):

Downloads

Downloads per month over past year