Members of this family are components of the mitochondrial large ribosomal subunit. Mature mitochondrial ribosomes consist of a small (37S) and a large (54S) subunit. The 37S subunit contains at least 33 different proteins and 1 molecule of RNA (15S). The 54S subunit contains at least 45 different proteins and 1 molecule of RNA (21S) .
Ribosomes are the particles that catalyse mRNA-directed protein synthesis in all organisms. The codons of the mRNA are exposed on the ribosome to allow tRNA binding. This leads to the incorporation of amino acids into the growing polypeptide chain in accordance with the genetic information. Incoming amino acid monomers enter the ribosomal A site in the form of aminoacyl-tRNAs complexed with elongation factor Tu (EF-Tu) and GTP. The growing polypeptide chain, situated in the P site as peptidyl-tRNA, is then transferred to aminoacyl-tRNA and the new peptidyl-tRNA, extended by one residue, is translocated to the P site with the aid the elongation factor G (EF-G) and GTP as the deacylated tRNA is released from the ribosome through one or more exit sites [PUBMED:11297922, PUBMED:11290319]. About 2/3 of the mass of the ribosome consists of RNA and 1/3 of protein. The proteins are named in accordance with the subunit of the ribosome which they belong to - the small (S1 to S31) and the large (L1 to L44). Usually they decorate the rRNA cores of the subunits.
Grohmann L, Graack HR, Kruft V, Choli T, Goldschmidt-Reisin S, Kitakawa M; , FEBS Lett. 1991;284:51-56.: Extended N-terminal sequencing of proteins of the large ribosomal subunit from yeast mitochondria. PUBMED:2060626 EPMC:2060626.