Updated project metadata. Chemical cross-linking coupled to mass spectrometry was used to study the folding of the client protein, beta-tubulin, by the chaperonin TRiC/CCT. Different complexes containing TRiC/CCT and/or the chaperone prefoldin were cross-linked in absence or presence of nucleotides with the homobifunctional, noncleavable reagent, disuccinimidyl suberate (DSS).