Only in this collision geometry do the positioning of the two RACK1s allow ZAK’s RACK1-interacting motif (RIM) to engage them and enabling its SAM domains to dimerize — the key step for activation. This activation is further negatively regulated by SERBP1 competing for the RACK1 interface. 4/4

ZAK is constitutively recruited to ribosomes via its RACK1-interacting helix (RIH), the eS27-pin, and the ES7-contacting patch. Upon stress, ribosome collisions generate a unique interface that enables specific contacts — the ES6-patch and the RIH-peptide. 3/4

Despite being the driving force behind the RSR, the interaction between ZAK and ribosomes has remained elusive for years. Here, we show how ZAK is recruited to ribosomes in native as well as stress-induced conditions, and how collision-specific interactions organized on RACK1 mediate activation. 2/4

Despite being the driving force behind the RSR, the interaction between ZAK and ribosomes has remained elusive for years. Here, we show how ZAK is recruited to ribosomes in native as well as stress-induced conditions, and how collision-specific interactions organized on RACK1 mediate activation. 2/4

Over the next six years, we’ll uncover the role of snoRNPs in ribosome assembly and disease. This project will be led in our lab by Roland Beckmann and Matthias Thoms @thomsmatt.bsky.social #ribosome #cryoEM

Our results finally explain the essential role of snR30 snoRNA! Check out the details in www.nature.com/articles/s41...