Fig. 2
From: The activity of TRAF RING homo- and heterodimers is regulated by zinc finger 1
The linker-helix and ZF1 of TRAF6 stabilise ubiquitin so that it is primed for attack. a Details of the molecular contacts between the RING dimer (two shades of green) and ubiquitin from the RZ1 complex (chains A, B and C). Predicted polar contacts are indicated with dashed lines. Carbon atoms coloured as in Fig. 1d, oxygen and nitrogen atoms coloured in red and blue, respectively. Numbering is as for D. rerio TRAF6. b Surface representation of the TRAF6–ubiquitin interaction. Critical residues for stabilisation are in pink. Arg126 is labelled as Arglink; Arg147 as ArgZF1. c Ubc13 conjugated to fluorescently labelled ubiquitin was used in discharge assays in combination with no E3, wild-type HsRZ3, or mutant forms of TRAF6 as indicated. d Quantification of the formation of diubiquitin. Each experiment was performed in duplicate; error bars indicate range of measurement. e Chain-building assay using the same mutants as in panel c. Reaction mixture was spiked with 10% fluorescently labelled ubiquitin to allow visualisation of the chains
