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 28S subunit protein. A pseudogene corresponding to this gene is found on chromosome 4. Alias Symbols: MRP-S25, RPMS25 Protein Interaction Partner: CEP76, TUBGCP3, TP53, GRSF1, UBC, C1QBP, MRPS9, MRPS35, MRPS22, MRPS7, MRPS16, MRPS18B, HNRNPAB, CAND1, COPS5, MME, ICT1, DDX56, Protein Size: 173