Fig. 4.

(A) Cartoon representation of the order of β strands in ^SFGFP-ssrA and circularly permuted variants. (B) Permuted variants (1 μM) were incubated overnight with ClpXP (1.25 μM ClpX₆; 2.5 μM ClpP₁₄), the SspB adaptor (1 μM), and 0, 50, or 300 μM ATP before assaying degradation by SDS-PAGE. (C) End-point experiments like those in panel B were performed but degradation was assayed by reduced 467-nm fluorescence. GFP-ssrA (circles); ^SFGFP-ssrA (squares); cp6-^SFGFP-ssrA (diamonds); cp7-^SFGFP-ssrA (triangles). The lines are fits to a modified form of the Hill equation. In the panel B and C experiments, an ATP-regeneration system was used.