The MT-TT gene is located on the p arm of the non-nuclear mitochondrial DNA at position 12 and it spans 66 base pairs.[4] The structure of a tRNA molecule is a distinctive folded structure which contains three hairpin loops and resembles a three-leafed clover.[5]
Function[]
MT-TT is a small 66 nucleotide RNA (human mitochondrial map position 15888-15953) that transfers the amino acid threonine to a growing polypeptide chain at the ribosome site of protein synthesis during translation.
Clinical significance[]
Myoclonic epilepsy with ragged-red fibers (MERRF)[]
MT-TT mutations result in complex IV deficiency of the mitochondrial respiratory chain, also known as the cytochrome c oxidase deficiency. Cytochrome c oxidase deficiency is a rare genetic condition that can affect multiple parts of the body, including skeletal muscles, the heart, the brain, or the liver. Common clinical manifestations include myopathy, hypotonia, and encephalomyopathy, lactic acidosis, and hypertrophic cardiomyopathy.[11] A 15915G>A mutation was found in a patient with cytochrome c oxidase deficiency with accompany symptoms of seizures, progressive hearing loss and muscle weakness.[12]
References[]
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, Eperon IC, Nierlich DP, Roe BA, Sanger F, Schreier PH, Smith AJ, Staden R, Young IG (April 1981). "Sequence and organization of the human mitochondrial genome". Nature. 290 (5806): 457–65. doi:10.1038/290457a0. PMID7219534.
^Graham BH, Waymire KG, Cottrell B, Trounce IA, MacGregor GR, Wallace DC (July 1997). "A mouse model for mitochondrial myopathy and cardiomyopathy resulting from a deficiency in the heart/muscle isoform of the adenine nucleotide translocator". Nature Genetics. 16 (3): 226–34. doi:10.1038/ng0797-226. PMID9207786.
^Grasbon-Frodl EM, Kösel S, Sprinzl M, von Eitzen U, Mehraein P, Graeber MB (April 1999). "Two novel point mutations of mitochondrial tRNA genes in histologically confirmed Parkinson disease". Neurogenetics. 2 (2): 121–7. doi:10.1007/s100480050063. PMID10369889.
^Yoon KL, Aprille JR, Ernst SG (May 1991). "Mitochondrial tRNA(thr) mutation in fatal infantile respiratory enzyme deficiency". Biochemical and Biophysical Research Communications. 176 (3): 1112–5. doi:10.1016/0006-291X(91)90399-R. PMID1645537.
^Reference, Genetics Home. "MT-TT gene". Genetics Home Reference.
^Nishino I, Seki A, Maegaki Y, Takeshita K, Horai S, Nonaka I, Goto Y (August 1996). "A novel mutation in the mitochondrial tRNA(Thr) gene associated with a mitochondrial encephalomyopathy". Biochemical and Biophysical Research Communications. 225 (1): 180–5. doi:10.1006/bbrc.1996.1150. PMID8769114.