Protein translocation: checkpoint role for SRP GTPase activation

Co-translational protein targeting by the signal recognition particle (SRP) relies on a complex series of structural rearrangements in the SRP and its receptor (SR). In order to precisely coordinate the individual steps, the GTPases of the SRP and the SR form a unique complex in which GTP hydrolysis is activated in a composite active site. A recent study provides new insights on the link between the GTPases and protein translocation.