Mitochondrial Ribosomal Protein S22 (MRPS22)

MRPS22 encodes a 28S subunit protein that does not seem to have a counterpart in prokaryotic and fungal-mitochondrial ribosomes. This gene lies telomeric of and is transcribed in the opposite direction from the forkhead box L2 gene. A pseudogene corresponding to this gene is found on chromosome Xq.

The deduced 360-amino acid MRPS22 protein has a calculated molecular mass of 41.3 kD. Removal of the predicted 29-amino acid N-terminal mitochondrial localization signal results in a mature 38.1-kD protein. Mouse and human MRPS22 share 78.3% amino acid identity. Thirteen transcripts were detected in testis using 5-prime and 3-prime RACE. The coding sequences were identical in all variants analyzed. The predicted mouse and human MRPS22 proteins share 78.9% amino acid identity.