SPATA5 is an 893 amino acid protein that localizes to cytoplasm and mitochondrion, and may be involved in morphological and functional mitochondrial transformations during spermatogenesis. Existing as three alternatively spliced isoforms, SPATA5 belongs to the AAA ATPase family and the AFG2 subfamily. The gene that encodes SPATA5 consists of more than 396,000 bases and maps to human chromosome 4q28.1. Housing nearly 900 genes, chromosome 4 represents approximately 6% of the human genome and is associated with Huntington's disease, Ellis-van Creveld syndrome, methylmalonic acidemia and polycystic kidney disease.