(A) Without nucleotide, monomers release in response to external force (left). k1 (middle) and k2 (right) of kinesin monomers pulled from the head and NL increase with force in both forward (positive forces) and backward directions. (B) With 1 mM ATP in solution, kinesin can release by force or hydrolysis of the bound nucleotide (left). MT release rates of the headand NL-pulled kinesins increase compared to the apo condition. (C) At 1 mM ADP, kinesin can release from MTs by force or ADP binding (left). NL-pulled kinesins show slower release under backward forces. Error bars represent 95% confidence intervals.
See also Figures S3 and S4.