Chemical potential differences provided by active or inactive Rab5 interactions (green, binding Rab5(GTP); grey, GTP hydrolysis, phosphate release and unbinding of Rab5(GDP)) affect the effective persistence length of EEA1, coupling chemical transformations of the GTPase to tether mechanics. The state transitions are indicated with colour-coded numbers: 1, unbound and extended EEA1; 2, extended EEA1–Rab5 complex; 3, collapsed EEA1–Rab5 complex; 4, unbound and collapsed EEA1. The transition paths are as follows: 1->2, capture (green); 2->3, collapse (red); 3->4, release (grey); 4->1, recovery (blue). The variables held constant during the transitions are indicated next to the respective transition paths.
