The AAA team: related ATPases with diverse functions

Abstract

A new family of related ATPases has emerged, characterized by a highly conserved AAA motif. This motif forms a 230-amino-acid domain that contains Walker homology sequences and imparts ATPase activity. Homology between AAA-family members is confined mostly to the AAA domain, although additional homology outside the AAA motif is present among closely related proteins. AAA proteins act in a variety of cellular functions, including cell-cycle regulation, protein degradation, organelle biogenesis and vesicle-mediated protein transport. The AAA domain is required for protein function, but its exact role and the specific activity that it confers on AAA proteins is still unclear. This review describes current understanding of the AAA protein family.

The mating pair formation system of conjugative plasmids—A versatile secretion machinery for transfer of proteins and DNA

“…The structure retains its symmetry and rigidity until all ATP molecules are hydrolyzed, at which point HP0525 can return to its nucleotide free form. Although sequence-unrelated, the structure of HP0525 is remarkably similar to that of the p97 AAA ATPase which, similarly to the related Nethylmaleimide-sensitive fusion protein (NSF), plays a central role in organelle assembly and membrane fusion processes in the endoplasmic reticulum and the Golgi apparatus (Patel and Latterich, 1998;Ye et al, 2001). It has therefore been proposed that VirB11-like proteins, by analogy to p97 and NSF, could serve as mechanical transducers providing the necessary mechanical force for the recruitment/assembly/disassembly of type IV secretion protein components, making them available for insertion into the nascent secretion apparatus and/or to facilitate substrate translocation across the inner membrane (Savvides et al, 2003).…”

ATPase-defective Mammalian VPS4 Localizes to Aberrant Endosomes and Impairs Cholesterol Trafficking

“…Vps4p belongs to the ATPases associated with cellular activities (AAA) family of proteins (Babst et al, 1997). Although AAA proteins participate in a wide variety of cellular activities, an emerging theme for their function is in molecular rearrangement and/or unfolding reactions (Confalonieri and Duguet, 1995;Patel and Latterich, 1998;Leonhard et al, 1999). It is possible, therefore, that Vps4p acts to modulate interactions between other components of the vacuolar sorting pathway, including other class E proteins.…”

Molecular Genetics of Vestibular Organ Development

“…AAA proteins are a group of ATPases that share common sequence features in addition to an ATP-binding motif. These proteins participate in a variety of cellular functions such as cell-cycle regulation, proteolysis, and membrane fusion (Patel and Latterich 1998). Using a positional cloning approach, Fidgetin was identified as the gene causing the inner ear and retinal phenotypes in the spontaneous mouse mutant fidget (Cox et al 2000).…”