Fig. 6.
SspB delivers ssrA-tagged substrates to ClpXP. (A) SspB (surface representation; 1OU8) binds to the AANDENY portion of the ssrA tag [37,52]. The C-terminal AA-COOH of the tag binds ClpX. (B) When SspB is disulfide bonded to the ssrA tag of a GFP substrate, both the adapter and substrate are degraded, requiring concurrent translocation of 3 polypeptides through the ClpX pore. Adapted with permission from ref. [58].