Humanin

Humanin is a peptide that is encoded in the mitochondrial genome by the 16S ribosomal RNA gene, MT-RNR2. Its structure contains a three-turn a-helix, and no symmetry.

The length of the peptide depends on where it is produced. If it is produced inside the mitochondria it will be 21 amino acids long. If it is produced outside the mitochondria, in the cytosol, it will be 24 amino acids long. Both peptides have been shown to have biological activity.