Mitochondrial Ribosomal Protein S18B (MRPS18B)

Mitochondria have their own translation system for production of 13 inner membrane proteins essential for oxidative phosphorylation. MRPS18B is a component of the small subunit of the mitochondrial ribosome that is encoded by the nuclear genome.

The deduced MRPS18B protein contains 258 amino acids and has a calculated molecular mass of 29.3 kD. Removal of a predicted 25-amino acid N-terminal mitochondrial localization signal results in a mature 26.5-kD protein. Humans have 3 MRPS18 proteins, MRPS18A, MRPS18B, and MRPS18C, that share sequence conservation only in their central regions. Mouse and human MRPS18B share 78.4% amino acid identity.