Ribosome recycling orchestrated by the ATP binding cassette (ABC) protein ABCE1 
can be considered as the final-or the first-step within the cyclic process of 
protein synthesis, connecting translation termination and mRNA surveillance with 
re-initiation. An ATP-dependent tweezer-like motion of the nucleotide-binding 
domains in ABCE1 transfers mechanical energy to the ribosome and tears the 
ribosome subunits apart. The post-recycling complex (PRC) then re-initiates mRNA 
translation. Here, we probed the so far unknown architecture of the 1-MDa PRC 
(40S/30S·ABCE1) by chemical cross-linking and mass spectrometry (XL-MS). Our 
study reveals ABCE1 bound to the translational factor-binding (GTPase) site with 
multiple cross-link contacts of the helix-loop-helix motif to the S24e ribosomal 
protein. Cross-linking of the FeS cluster domain to the ribosomal protein S12 
substantiates an extreme lever-arm movement of the FeS cluster domain during 
ribosome recycling. We were thus able to reconstitute and structurally analyse a 
key complex in the translational cycle, resembling the link between translation 
initiation and ribosome recycling.