Mammalian mitochondrial ribosomal proteins are encoded by
nuclear genes and help in protein synthesis within the
mitochondrion. Mitochondrial ribosomes (mitoribosomes) consist of a
small 28S subunit and a large 39S subunit. They have an estimated
75% protein to rRNA composition compared to prokaryotic ribosomes,
where this ratio is reversed. Another difference between mammalian
mitoribosomes and prokaryotic ribosomes is that the latter contain
a 5S rRNA. Among different species, the proteins comprising the
mitoribosome differ greatly in sequence, and sometimes in
biochemical properties, which prevents easy recognition by sequence
homology. This gene encodes a 39S subunit protein, a part of which
was originally isolated by its ability to recognize tyrosinase in
an HLA-A24-restricted fashion.
