Figure 1. Canonical Hsp70 biochemical cycle.

The model takes into account four states in Hsp70 (NBD is schematically represented here in green, SBD in orange), which are defined by substrate binding and by the nature of the bound nucleotide (ADP or ATP). The rates of the substrate binding/unbinding process (horizontal blue lines) are influenced by the nucleotide ($k_{ATP}^{on}$, $k_{ATP}^{off}$, $k_{ATP}^{on}$, $k_{ATP}^{off}$). ADP-bound states are converted to ATP-bound states through a nucleotide exchange process (vertical solid blue lines) with rates k_DT , $k_{DT}^S$. The ATP to ADP conversion can occur by means of either a nucleotide exchange process (dashed blue lines) with rates $k_{TD}^{ex}$, $k_{TD}^{ex,S}$ or ATP-hydrolysis (red lines) with rates k_h, $k_h^S$.

DOI: http://dx.doi.org/10.7554/eLife.02218.003