39S ribosomal protein L20, mitochondrial is a protein that in humans is encoded by the MRPL20gene.
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. A pseudogene corresponding to this gene is found on chromosome 21q.
Suzuki T, Terasaki M, Takemoto-Hori C, et al. (2001). "Structural compensation for the deficit of rRNA with proteins in the mammalian mitochondrial ribosome. Systematic analysis of protein components of the large ribosomal subunit from mammalian mitochondria". J. Biol. Chem. 276 (24): 21724–36. doi:10.1074/jbc.M100432200. PMID11279069.
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.
Koc EC, Burkhart W, Blackburn K, et al. (2001). "The large subunit of the mammalian mitochondrial ribosome. Analysis of the complement of ribosomal proteins present". J. Biol. Chem. 276 (47): 43958–69. doi:10.1074/jbc.M106510200. PMID11551941.