Reactome | Mitochondrial translation termination

Mitochondrial translation termination

Stable Identifier

R-HSA-5419276

DOI

10.3180/R-HSA-5419276.5

Type

Pathway

Species

Homo sapiens

Compartment

mitochondrial matrix, mitochondrial inner membrane

ReviewStatus

5/5

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Translation is terminated for 11 of the 13 mitochondrially encoded proteins when MTRF1L (MTRF1a) recognizes a UAA or UAG termination codon in the mRNA at the A site of the ribosome (Soleimanpour-Lichaei et al. 2007, reviewed in Richter et al. 2010, Chrzanowska-Lightowlers et al. 2011. Christian and Spremulli 2012). Translation of the MT-CO1 and MT-ND6 proteins is terminated at an AGG codon and an AGA codon, respectively. These two noncanonical stop codons are recognized by MTRF1. GTP is hydrolyzed, and the aminoacyl bond between the translated polypeptide and the final tRNA at the P site is hydrolyzed by the 39S ribosomal subunit, releasing the translated polypeptide. MRRF (RRF) and GFM2:GTP (EF-G2mt:GTP) then act to release the remaining tRNA and mRNA from the ribosome and dissociate the 55S ribosome into 28S and 39S subunits.

Literature References

PubMed ID	Title	Journal	Year
21118119	Translation termination in human mitochondrial ribosomes Richter, R, Pajak, A, Dennerlein, S, Rozanska, A, Lightowlers, RN, Chrzanowska-Lightowlers, ZM	Biochem. Soc. Trans.	2010
21873426	Termination of protein synthesis in mammalian mitochondria Chrzanowska-Lightowlers, ZM, Pajak, A, Lightowlers, RN	J. Biol. Chem.	2011
22172991	Mechanism of protein biosynthesis in mammalian mitochondria Christian, BE, Spremulli, LL	Biochim. Biophys. Acta	2012
17803939	mtRF1a is a human mitochondrial translation release factor decoding the major termination codons UAA and UAG Soleimanpour-Lichaei, HR, Kühl, I, Gaisne, M, Passos, JF, Wydro, M, Rorbach, J, Temperley, R, Bonnefoy, N, Tate, W, Lightowlers, R, Chrzanowska-Lightowlers, ZM	Mol. Cell	2007