Escherichia coli BepA has proteolytic and chaperone‐like functions and acts in the degradation and biogenesis of β‐barrel outer membrane proteins (OMP). The tetratricopeptide repeat (TPR) domain of BepA (orange) interacts with proteins of the β‐barrel assembly machinery (BAM) complex (PDB code: 5D0O) as well as a substrate OMP (LptD; not shown), as visualized by in vivo photo‐cross‐linking. For details, see the article by Daimon et al . on pp. 760–776 of this issue.