Fig. 7: Proposed model for DnaJB8–HspA1A–substrate relationship.
From: Regulatory inter-domain interactions influence Hsp70 recruitment to the DnaJB8 chaperone
Schematic of proposed DnaJB8 model. Domains are shown as JD (red spheres), CTD (green spheres), G/F (blue spheres), S/T (light blue spheres), and also HspA1A (dark blue spheres) and substrate (purple line) are shown. DnaJB8 domain sizes are displayed scaled to the relative Rh values derived from DLS experiments (HspA1A not drawn to scale). a DnaJB8 forms a fundamental oligomeric species through aromatic contacts in the G/F and S/T domains ranging from monomer to octamer. b The JD–CTD engaged state, where the JD is stabilized by CTD and helix 5 (G/F) contacts, can form larger polydisperse oligomers (>100 nm). The JD–CTD disengaged state (bottom) is needed to engage with HspA1A. We illustrate our hypothesis where substrate binding may allosterically disrupt the JD–CTD interaction to allow the recruitment of HspA1A to the freed JD–CTD binding face, enabling subsequent handoff of the substrate to HspA1A.
