Mitochondrial Ribosomal Protein S18A (MRPS18A)

Mitochondria have their own translation system for production of 13 proteins essential for oxidative phosphorylation. MRPS18A is 1 of more than 70 protein components of mitochondrial ribosomes that are encoded by the nuclear genome.

The deduced MRPS18A protein contains 196 amino acids and has a calculated molecular mass of 22.2 kD. Removal of a predicted 37-amino acid N-terminal mitochondrial localization signal results in a mature 18.4-kD protein. Mrps18 protein is present in E. coli, whereas other organisms contain several Mrps18 orthologs. Humans have 3 MRPS18 proteins, MRPS18A, MRPS18B, and MRPS18C, that share homology only in their central regions. Mouse and human MRPS18A share 80.1% amino acid identity.