MRPL55 explained

39S ribosomal protein L55, mitochondrial is a protein that in humans is encoded by the MRPL55 gene.^[1]

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.^[2]

Further reading

• Bonaldo MF, Lennon G, Soares MB . Normalization and subtraction: two approaches to facilitate gene discovery. . Genome Res. . 6 . 9 . 791–806 . 1997 . 8889548 . 10.1101/gr.6.9.791 . free .
• Dias Neto E, Correa RG, Verjovski-Almeida S, etal . Shotgun sequencing of the human transcriptome with ORF expressed sequence tags. . Proc. Natl. Acad. Sci. U.S.A. . 97 . 7 . 3491–3496 . 2000 . 10737800 . 10.1073/pnas.97.7.3491 . 16267 . 2000PNAS...97.3491D . free .
• Koc EC, Burkhart W, Blackburn K, etal . The large subunit of the mammalian mitochondrial ribosome. Analysis of the complement of ribosomal proteins present. . J. Biol. Chem. . 276 . 47 . 43958–43969 . 2001 . 11551941 . 10.1074/jbc.M106510200 . free .
• O'Brien TW . Evolution of a protein-rich mitochondrial ribosome: implications for human genetic disease. . Gene . 286 . 1 . 73–79 . 2002 . 11943462 . 10.1016/S0378-1119(01)00808-3 .
• Strausberg RL, Feingold EA, Grouse LH, etal . Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences. . Proc. Natl. Acad. Sci. U.S.A. . 99 . 26 . 16899–16903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . 2002PNAS...9916899M . free .
• Zhang Z, Gerstein M . Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome. . Genomics . 81 . 5 . 468–480 . 2003 . 12706105 . 10.1016/S0888-7543(03)00004-1 .
• Clark HF, Gurney AL, Abaya E, etal . The secreted protein discovery initiative (SPDI), a large-scale effort to identify novel human secreted and transmembrane proteins: a bioinformatics assessment. . Genome Res. . 13 . 10 . 2265–2270 . 2003 . 12975309 . 10.1101/gr.1293003 . 403697 .
• Ota T, Suzuki Y, Nishikawa T, etal . Complete sequencing and characterization of 21,243 full-length human cDNAs. . Nat. Genet. . 36 . 1 . 40–45 . 2004 . 14702039 . 10.1038/ng1285 . free .
• Gerhard DS, Wagner L, Feingold EA, etal . The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). . Genome Res. . 14 . 10B . 2121–2127 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 .
• Gregory SG, Barlow KF, McLay KE, etal . The DNA sequence and biological annotation of human chromosome 1. . Nature . 441 . 7091 . 315–321 . 2006 . 16710414 . 10.1038/nature04727 . 2006Natur.441..315G . free .

Notes and References

1. Web site: Entrez Gene: MRPL55 mitochondrial ribosomal protein L55.
2. Web site: Entrez Gene: MRPL55 mitochondrial ribosomal protein L55.