39S ribosomal protein L55, mitochondrial is a protein that in humans is encoded by the MRPL55gene.[5]
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. Multiple transcript variants encoding two different isoforms were identified through sequence analysis.[5]
O'Brien TW (2002). "Evolution of a protein-rich mitochondrial ribosome: implications for human genetic disease". Gene. 286 (1): 73–79. doi:10.1016/S0378-1119(01)00808-3. PMID11943462.
Zhang Z, Gerstein M (2003). "Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome". Genomics. 81 (5): 468–480. doi:10.1016/S0888-7543(03)00004-1. PMID12706105.