AAA Proteins - Domain Structure of AAA-type ATPases

Domain Structure of AAA-type ATPases

All AAA+ proteins have a mixed alpha/beta domain that binds and hydrolyzes nucleotide. Most AAA+ proteins have a second domain that comprises the AAA+ module: an all alpha-helical domain, often called the lid domain, that is C-terminal of the alpha/beta domain. Most AAA+ proteins have additional domains that are used for oligomerization, substrate binding and/or regulation. These domains can lie N- or C-terminal to the AAA+ module.

Some classes of AAA proteins have an N-terminal Non-ATPase domain which is followed by either one or two AAA domains (D1 and D2). In some proteins with two AAA domains, both are evolutionarily well conserved (like in Cdc48/p97). In others, either the D2 domain (like in Pex1p and Pex6p) or the D1 domain (in Sec18p/NSF) is better conserved in evolution.