Mammalian mitochondrial ribosomes (mitoribosomes) are responsible for protein synthesis within the mitochondrion. The mitoribosomes are composed of a 4:1 ratio of protein to RNA, with the proteins forming two subunits, the 28S subunit and the 39S subunit. Across species, the proteins that make up the mitoribosome subunits vary greatly in sequence, preventing easy recognition by sequence homology. MRP-S9 (mitochondrial 28S ribosomal protein S9), also known as RPMS9, is a 396 amino acid mitochondrial ribosomal protein. Localized to mitochondria, MRP-S9 is present in the 28S subunit of the mitoribosomes, which comprises a 12S rRNA and at least 30 distinct proteins.
28S ribosomal protein S9; 28S ribosomal protein S9, mitochondrial; mitochondrial; Mitochondrial small ribosomal subunit protein uS9m; MRP-S9; MRPS9; RPMS9; S9mt