Updated publication reference for PubMed record(s): 34854379. Chemical cross-linking coupled to mass spectrometry was used to study two tRNA ligase complexes, one consisting of subunits RTCB, DDX1, CGI-99, FAM98B and Ashwin (“full tRLC”) and one lacking Ashwin (“core tRLC”). Cross-linking was performed using the homobifunctional, noncleavable reagent, disuccinimidyl suberate (DSS).