Paraplegin [SEP] chromosome
Paraplegin
Paraplegin is a protein that in humans is encoded by the "SPG7" gene located on chromosome 16.
Structure.
The SPG7 gene contains 21 exons and encodes for a protein that is approximately 88 kDa in size. Two transcript variants encoding distinct isoforms have been identified for this gene. 
The structure of the SPG7 resolved by X-ray crystallography reveals that the protein functions as a hexamer and is structurally most similar to bacterial FtSH proteases. It contains an FtsH-homology protease domain as well as an
AFG3L2
AFG3 ATPase family gene 3-like 2 ("S. cerevisiae") is a protein that in humans is encoded by the "AFG3L2" gene.
This gene encodes a protein localized in mitochondria and closely related to paraplegin. The paraplegin gene is responsible for an autosomal recessive form of hereditary spastic paraplegia. This gene is a candidate gene for other hereditary spastic paraplegias or neurodegenerative disorders as well as spastic ataxia-neuropathy syndrome.