Fig. 1

PanB from Mycobacterium tuberculosis is pupylated at a single lysine residue (K212). a Formation of a covalent ^MtbPup ~ ^MtbPanB conjugate analysed by SDS–PAGE and Coomassie staining after incubation of 6 μM ^MtbPanB and 12 μM ^MtbPup with 1 μM ^MtbPafA in the presence of 5 mM ATP. The variant K212A does not show formation of a conjugate band over the same time-course. b Top and sideview of the ^MtbPanB decamer (pdb code 1OY0) in surface representation (grey). The pupylated lysine K212 is highlighted in red. c Alignment of PanB orthologs from representative actinobacteria with only the portion around K212 shown. Lysine K212 of ^MtbPanB (shown in red) is conserved in all proteasome-harboring actinobacteria (indicated in the alignment by a black dot). The degree of conservation is expressed as different shades of blue with low conservation light blue and high conservation dark blue