MT-TV (mitochondrial)

Transfer RNA

mitochondrially encoded tRNA valine

Identifiers
Symbol| MT-TV
Alt. symbols| MTTV
NCBI gene| 4577
HGNC| 7500
OMIM| 590105
RefSeq| NC_001807
Other data
Locus| Chr. MT [1]

Mitochondrially encoded tRNA valine also known as MT-TV is a transfer RNA which in humans is encoded by the mitochondrial MT-TV gene.[1]

## Structure

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The MT-TV gene is located on the p arm of the non-nuclear mitochondrial DNA at position 12 and it spans 69 base pairs.[2] The structure of a tRNA molecule is a distinctive folded structure which contains three hairpin loops and resembles a three-leafed clover.[3]

## Function

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MT-TV is a small 69 nucleotide RNA (human mitochondrial map position 1602-1670) that transfers the amino acid valine to a growing polypeptide chain at the ribosome site of protein synthesis during translation.

In animals, more specifically vertebrates, MT-tRNAVal performs an integral structural role for the mitoribosome by filling in the position of a missing 5S mitoribosomal RNA.[4]

## Clinical significance

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Mutations in MT-TV which impair oxidate phosphorylation result in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). MELAS is a rare mitochondrial disorder known to affect many parts of the body, especially the nervous system and the brain. Symptoms of MELAS include recurrent severe headaches, muscle weakness (myopathy), hearing loss, stroke-like episodes with a loss of consciousness, seizures, and other problems affecting the nervous system. Two specific mutations of 1642G>A and 1644G>A have been found to result in the disease.[5]

Changes in the gene have also been associated with Leigh's syndrome, a progressive brain disorder characterized by vomiting, seizures, delayed development, muscle weakness, problems with movement, heart disease, kidney problems, and difficulty breathing. Symptoms typically appear in infancy or early childhood. A 1624C>T mutation has been linked to this disease.[6]

Other clinical manifestations associated with MT-TV mutations have included recurrent migraine headaches, muscle weakness and poor coordination, hearing loss, learning disabilities, dementia, and more. It has not been found why such mutations cause symptoms of these diseases.[5] A 1606A>G mutation resulted in ataxia accompanied by progressive seizures, mental deterioration, and hearing loss.[7] Cardiomyopathy, which weakens and enlarges the heart muscle, has also been reported in a small number of affected individuals.[5]

## References

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1. ^ Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, et al. (April 1981). "Sequence and organization of the human mitochondrial genome". Nature. 290 (5806): 457–65\. Bibcode:1981Natur.290..457A. doi:10.1038/290457a0. PMID 7219534. S2CID 4355527.
2. ^ "MT-TV mitochondrially encoded tRNA valine [Homo sapiens (human)] \- Gene - NCBI". www.ncbi.nlm.nih.gov.
3. ^ "tRNA / transfer RNA". Learn Science at Scitable.
4. ^ Brown A, Amunts A, Bai XC, Sugimoto Y, Edwards PC, Murshudov G, et al. (November 2014). "Structure of the large ribosomal subunit from human mitochondria". Science. 346 (6210): 718–722\. Bibcode:2014Sci...346..718B. doi:10.1126/science.1258026. PMC 4246062. PMID 25278503.
5. ^ a b c "MT-TH gene". Genetics Home Reference. This article incorporates text from this source, which is in the public domain.
6. ^ McFarland R, Clark KM, Morris AA, Taylor RW, Macphail S, Lightowlers RN, Turnbull DM (February 2002). "Multiple neonatal deaths due to a homoplasmic mitochondrial DNA mutation". Nature Genetics. 30 (2): 145–6\. doi:10.1038/ng819. PMID 11799391. S2CID 10940372.
7. ^ Tiranti V, D'Agruma L, Pareyson D, Mora M, Carrara F, Zelante L, et al. (January 1998). "A novel mutation in the mitochondrial tRNA(Val) gene associated with a complex neurological presentation". Annals of Neurology. 43 (1): 98–101\. doi:10.1002/ana.410430116. PMID 9450773. S2CID 25775432.

## External links

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* GeneReviews/NCBI/NIH/UW entry on Mitochondrial DNA-Associated Leigh Syndrome and NARP

* v
* t
* e

Mitochondrial proteins

Outer membrane|

| fatty acid degradation|

* Carnitine palmitoyltransferase I
* Long-chain-fatty-acid—CoA ligase

|

tryptophan metabolism|

* Kynureninase

monoamine neurotransmitter
metabolism|

* Monoamine oxidase

Intermembrane space|

* Adenylate kinase
* Creatine kinase

Inner membrane|

| oxidative phosphorylation|

* Coenzyme Q – cytochrome c reductase
* Cytochrome c
* NADH dehydrogenase
* Succinate dehydrogenase

|

pyrimidine metabolism|

* Dihydroorotate dehydrogenase

mitochondrial shuttle|

* Malate-aspartate shuttle
* Glycerol phosphate shuttle

steroidogenesis|

* Cholesterol side-chain cleavage enzyme
* Steroid 11-beta-hydroxylase
* Aldosterone synthase

other|

* Glutamate aspartate transporter
* Glycerol-3-phosphate dehydrogenase
* ATP synthase
* Carnitine palmitoyltransferase II
* Uncoupling protein

Matrix|

| citric acid cycle|

* Citrate synthase
* Aconitase
* Isocitrate dehydrogenase
* Oxoglutarate dehydrogenase complex
* Succinyl coenzyme A synthetase
* Fumarase
* Malate dehydrogenase

|

anaplerotic reactions|

* Aspartate transaminase
* Glutamate dehydrogenase
* Pyruvate dehydrogenase complex

urea cycle|

* Carbamoyl phosphate synthetase I
* Ornithine transcarbamylase
* N-Acetylglutamate synthase

alcohol metabolism|

* ALDH2

* PMPCB

Other/to be sorted|

* Frataxin
* Mitochondrial membrane transport protein
* Mitochondrial permeability transition pore
* Mitochondrial carrier
* Translocator protein

Mitochondrial DNA|

| Complex I|

* MT-ND1
* MT-ND2
* MT-ND3
* MT-ND4
* MT-ND4L
* MT-ND5
* MT-ND6

|

Complex III|

* MT-CYB

Complex IV|

* MT-CO1
* MT-CO2
* MT-CO3

ATP synthase|

* MT-ATP6
* MT-ATP8

tRNA|

* MT-TA
* MT-TC
* MT-TD
* MT-TE
* MT-TF
* MT-TG
* MT-TH
* MT-TI
* MT-TK
* MT-TL1
* MT-TL2
* MT-TM
* MT-TN
* MT-TP
* MT-TQ
* MT-TR
* MT-TS1
* MT-TS2
* MT-TT
* MT-TV
* MT-TW
* MT-TY

see also mitochondrial diseases

This article incorporates text from the United States National Library of Medicine, which is in the public domain.
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