InterPro domain: IPR009686

This is the AAA ATPase domain found at the C-terminal of plant senescence-associated proteins and spartin. In Hemerocallis, petals have a genetically based program that leads to senescence and cell death approximately 24 hours, after the flower opens, and it is believed that senescence proteins produced around that time have a role in this program [ 1 ]. This domain is also found at the C-terminal of Spartin, a protein from higher vertebrates associated with endosomal trafficking and microtubule dynamics [ 2 ]. Spartin functions presynaptically with endocytic adaptor Eps15 to regulate synaptic growth and function. Mutations in human spartin gene cause Troyer syndrome, a hereditary spastic paraplegia [ 3 ]. This AAA ATPase domain similar to other AAA proteins contain an alpha/beta nucleotide-binding domain (NBD) and a smaller four-helix bundle domain (HBD) [ 4 ]. Uniquely among AAA structures, spastin has two helices (N-terminal alpha1 and C-terminal alpha11) that embrace the NBD [ 5 ].

1. Identification of senescence-associated genes from daylily petals. Plant Mol. Biol. 40, 237-48
2. The identification of a conserved domain in both spartin and spastin, mutated in hereditary spastic paraplegia. Genomics 81, 437-41
3. Spartin regulates synaptic growth and neuronal survival by inhibiting BMP-mediated microtubule stabilization. Neuron 77, 680-95
4. Structural basis of microtubule severing by the hereditary spastic paraplegia protein spastin. Nature 451, 363-7