Updated project metadata. To understand the orientation of Hsp70 Ssb on the ribosome in living Saccharomyces cerevisiae cells we incorporated the noncanonical, photoactivatable amino acid p-benzoyl-L-phenylalanine (Bpa) in place of specific individual endogenous amino acids in Ssb1. To identify the proteins to which Ssb1Bpa crosslinked we performed mass spectrometry. The results revealed that Bpa incorporated at the tip of the “lid” subdomain cross linked to the nascent chain associated complex (NAC), while Bpa incorporated into further down the lid crosslinked to ribosomal protein uL29.