Figure 8.

(A) GFP-g₁₃senyalaa contains 13 glycines between the native barrel of GFP and a partial ssrA degron and is not degraded by ClpXP. (B) Effects of tyrosine substitutions at the N-terminal seven positions of the poly-glycine region of GFP-g₁₃senyalaa on the maximal rate of ClpXP degradation (Bell et al., 2019). (C) Effects of position-4 side chain properties on ClpXP degradation (Bell et al., 2019). (D) Degradation of variants with threonine or valine at position 4 of the polyglycine region (Bell et al., 2019). (E) During unfolding, degron side chains 3-5 amino acids from the native domain of a substrate are the most important determinants of grip and are positioned to interact with the pore-1 loops of subunits A and B, near the top of the ClpX channel.