HemK2 protein, encoded on human chromosome 21, methylates translation termination factor eRF1.
The ubiquitous tripeptide Gly-Gly-Gln in class 1 polypeptide release factors triggers polypeptide release on ribosomes. The Gln residue in both bacterial and yeast release factors is N5-methylated, despite their distinct evolutionary origin. Methylation of eRF1 in yeast is performed by the heterodimeric methyltransferase (MTase) Mtq2p/Trm112p, and requires eRF3 and GTP. Homologues of yeast Mtq2p and Trm112p are found in man, annotated as an N6-DNA-methyltransferase and of unknown function. Here we show that the human proteins methylate human and yeast eRF1.eRF3.GTP in vitro, and that the MTase catalytic subunit can complement the growth defect of yeast strains deleted for mtq2.
Figaro
Sabine
S
IBPC, CNRS, UPR 9073, 13 rue Pierre et Marie Curie, 75005 Paris, France.
Scrima
Nathalie
N
Buckingham
Richard H
RH
Heurgué-Hamard
Valérie
V
D000595:Amino Acid Sequence; D000818:Animals; D002891:Chromosomes, Human, Pair 21; D005816:Genetic Complementation Test; D006801:Humans; D008780:Methyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D010454:Peptide Termination Factors / Q000378:metabolism*; D011496:Protein Methyltransferases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
C489002:ETF1 protein, human; D010454:Peptide Termination Factors; D029701:Saccharomyces cerevisiae Proteins; C497157:MTQ2 protein, S cerevisiae; D008780:Methyltransferases; D011496:Protein Methyltransferases; C531112:HemK2alpha protein, human