39S ribosomal protein L22, mitochondrial is a protein that in humans is encoded by the MRPL22gene.[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 that belongs to the L22 ribosomal protein family. A pseudogene corresponding to this gene is found on chromosome 4q. Two transcript variants encoding different isoforms have been found for this gene.[5]
Kenmochi N, Suzuki T, Uechi T, et al. (2001). "The human mitochondrial ribosomal protein genes: mapping of 54 genes to the chromosomes and implications for human disorders". Genomics. 77 (1–2): 65–70. doi:10.1006/geno.2001.6622. PMID11543634.
O'Brien TW (2002). "Evolution of a protein-rich mitochondrial ribosome: implications for human genetic disease". Gene. 286 (1): 73–9. 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): 468–80. doi:10.1016/S0888-7543(03)00004-1. PMID12706105.