Graphical Abstract (IMAGE) UT Southwestern Medical Center Caption In the native state, DnaJB8 chaperone forms soluble oligomers in which the J domain (JD, red) is engaged in electrostatic interactions with the C-terminal domain (CTD, green) and thus not available for Hsp70 binding (blue). We propose that substrate (purple) binding disrupts the JD-CTD interaction, exposing the JD and enabling the recruitment of Hsp70 to the substrate-activated DnaJB8 protein. Credit UT Southwestern Medical Center Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.