What happens to dynein when ATP binds to its AAA1 domain?
Nucleotide dependent affinity switching allows dynein stepping without dragging cargo backward and enables high force production. In high affinity state stalk MTBD binds tightly to microtubule lattice resisting detachment under piconewton loads up to 7 pN corresponding to apo or ADP bound heavy chain state with stalk helices registry CC1 CC2 in specific alignment. When ATP enters AAA1 pocket AAA ring closure pulls AAA5 and buttress subdomains sliding stalk coiled coils by half heptad altering MTBD helices arrangement converting to low affinity conformation reducing binding energy about tenfold
Ref: Imamula et al., Cell 2007 – Detachment upon ATP binding to AAA1 causes dynein release.
