Figure 2
From: Unscrambling an egg: protein disaggregation by AAA+ proteins
Structural features of AAA+ proteins. (A) Domain organization and cooperating proteins of AAA+ chaperones. N-terminal domains of AAA+ proteins are diverse and are in most cases involved in substrate recognition, either directly or indirectly by serving as a binding platform for adaptor proteins. In the case of Torsin A, the N-domain represents a membrane-spanning region. The first AAA domains of ClpB and ClpC are interrupted by a middle domain (M-domain) of variable length. ClpP-association of ClpA, ClpC and ClpX is mediated by a conserved docking site (P). Adaptor proteins, cooperating proteins and functions of the corresponding AAA+ proteins are given. The ClpX adaptor proteins SspB, RssB and UmuD target SsrA-tagged proteins, the alternative sigma factor σS and UmuD' for degradation by ClpXP, respectively [90–93]. (B) Structure of monomeric T. thermophilus ClpB and E. coli ClpA. The colour code of the individual domains is equivalent to (A). AMPPNP (ClpB) or ADP (ClpA) is shown as CPK model in grey.