MRPS21 explained

28S ribosomal protein S21, mitochondrial is a protein that in humans is encoded by the MRPS21 gene.^{[1] [2]}

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and assist protein synthesis within the mitochondrion.^[1] 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 28S subunit protein that belongs to the ribosomal protein S21P family.^[2] Pseudogenes corresponding to this gene are found on chromosomes 1p, 1q, 9p, 10p, 10q, 16q, and 17q.^[3] Available sequence data analyses identified splice variants that differ in the 5' UTR; both transcripts encode the same protein.^[4]

Further reading

Gerhard DS . The Status, Quality, and Expansion of the NIH Full-Length cDNA Project: The Mammalian Gene Collection (MGC) . Genome Res. . 14 . 10B . 2121–7 . 2004 . 15489334 . 10.1101/gr.2596504 . 528928 . vanc. Wagner L . Feingold EA . 3 . Shenmen . CM . Grouse . LH . Schuler . G . Klein . SL . Old . S . Rasooly . R .

• Zhang Z, Gerstein M . Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome . Genomics . 81 . 5 . 468–80 . 2003 . 12706105 . 10.1016/S0888-7543(03)00004-1 .
• Strausberg RL . 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 . 16899–903 . 2003 . 12477932 . 10.1073/pnas.242603899 . 139241 . vanc. Feingold EA . Grouse LH . 3 . Derge . JG . Klausner . RD . Collins . FS . Wagner . L . Shenmen . CM . Schuler . GD . 2002PNAS...9916899M . free .
• Kenmochi N . The human mitochondrial ribosomal protein genes: mapping of 54 genes to the chromosomes and implications for human disorders . Genomics . 77 . 1–2 . 65–70 . 2001 . 11543634 . 10.1006/geno.2001.6622 . vanc. Suzuki T . Uechi T . 3 . Magoori . Mika . Kuniba . Mariko . Higa . Sayomi . Watanabe . Kimitsuna . Tanaka . Tatsuo .
• Suzuki T . Proteomic analysis of the mammalian mitochondrial ribosome. Identification of protein components in the 28 S small subunit . J. Biol. Chem. . 276 . 35 . 33181–95 . 2001 . 11402041 . 10.1074/jbc.M103236200 . vanc. Terasaki M . Takemoto-Hori C . 3 . Hanada . T . Ueda . T . Wada . A . Watanabe . K . free .
• Cavdar Koc E . The small subunit of the mammalian mitochondrial ribosome. Identification of the full complement of ribosomal proteins present . J. Biol. Chem. . 276 . 22 . 19363–74 . 2001 . 11279123 . 10.1074/jbc.M100727200 . vanc. Burkhart W . Blackburn K . 3 . Moseley . A . Spremulli . LL . free .
• Yu W . Large-Scale Concatenation cDNA Sequencing . Genome Res. . 7 . 4 . 353–8 . 1997 . 9110174 . 10.1101/gr.7.4.353. 139146 . vanc. Andersson B . Worley KC . 3 . Muzny . DM . Ding . Y . Liu . W . Ricafrente . JY . Wentland . MA . Lennon . G .
• Andersson B . A "double adaptor" method for improved shotgun library construction . Anal. Biochem. . 236 . 1 . 107–13 . 1996 . 8619474 . 10.1006/abio.1996.0138 . vanc. Wentland MA . Ricafrente JY . 3 . Liu . W . Gibbs . RA .

Notes and References

1. Kenmochi N, Suzuki T, Uechi T, Magoori M, Kuniba M, Higa S, Watanabe K, Tanaka T . The human mitochondrial ribosomal protein genes: mapping of 54 genes to the chromosomes and implications for human disorders . Genomics . 77 . 1–2 . 65–70 . September 2001 . 11543634 . 10.1006/geno.2001.6622 .
2. Cavdar Koc E, Burkhart W, Blackburn K, Moseley A, Spremulli LL . The small subunit of the mammalian mitochondrial ribosome. Identification of the full complement of ribosomal proteins present . J. Biol. Chem. . 276 . 22 . 19363–74 . June 2001 . 11279123 . 10.1074/jbc.M100727200 . free .
3. Zhang Z, Gerstein M . Identification and characterization of over 100 mitochondrial ribosomal protein pseudogenes in the human genome . Genomics . 81 . 5 . 468–80 . May 2003 . 12706105 . 10.1016/S0888-7543(03)00004-1.
4. Web site: Entrez Gene: MRPS21 mitochondrial ribosomal protein S21.