Figure 5: ClpX activates ClpP in a similar manner and is competed by ADEP.
From: AAA+ chaperones and acyldepsipeptides activate the ClpP protease via conformational control
(a) Schematic of the SaClpX-mediated unfolding of SsrA-tagged GFP and its subsequent degradation by SaClpP. (Note, the precise path of product peptide release is unclear and under debate.) (b) SaClpXP–GFP assay. The initial slopes of the decrease in GFP fluorescence of the fluorescence-time courses were quantified and are displayed in the bar graph. A Coomassie-stained gel of these samples showing GFP after 3 h at 30 °C indicates that wild-type, D172A, D172N, and D170A SaClpP are capable of protein degradation, while S98A, T169A and R171A SaClpP are not. This is consistent with in-gel GFP fluorescence measurements. See Supplementary Fig. 7n,o for uncropped gel images. (c,d) ADEP7 and ADEP4 disrupt SaClpXP-mediated GFP unfolding with an IC50 value comparable to the concentration of SaClpP14. (e) Schematic showing how the binding of ADEP to SaClpP14 prevents the binding of ClpX6 and thus GFP unfolding. Mean±s.d. are given in all panels (N=3). IC50 values are given with fitting errors.
