The zinc finger protein Ynr046w is plurifunctional and a component of the eRF1 methyltransferase in yeast

J Biol Chem. 2006 Nov 24;281(47):36140-8. doi: 10.1074/jbc.M608571200. Epub 2006 Sep 28.

Abstract

Protein release factor eRF1 in Saccharomyces cerevisiae, in complex with eRF3 and GTP, is methylated on a functionally crucial Gln residue by the S-adenosylmethionine-dependent methyltransferase Ydr140w. Here we show that eRF1 methylation, in addition to these previously characterized components, requires a 15-kDa zinc-binding protein, Ynr046w. Co-expression in Escherichia coli of Ynr046w and Ydr140w allows the latter to be recovered in soluble form rather than as inclusion bodies, and the two proteins co-purify on nickel-nitrilotriacetic acid chromatography when Ydr140w alone carries a His tag. The crystal structure of Ynr046w has been determined to 1.7 A resolution. It comprises a zinc-binding domain built from both the N- and C-terminal sequences and an inserted domain, absent from bacterial and archaeal orthologs of the protein, composed of three alpha-helices. The active methyltransferase is the heterodimer Ydr140w.Ynr046w, but when alone, both in solution and in crystals, Ynr046w appears to be a homodimer. The Ynr046w eRF1 methyltransferase subunit is shared by the tRNA methyltransferase Trm11p and probably by two other enzymes containing a Rossman fold.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Escherichia coli / metabolism
  • Glutamine / chemistry
  • Humans
  • Methyltransferases / metabolism
  • Methyltransferases / physiology*
  • Molecular Sequence Data
  • Nickel / chemistry
  • Peptide Termination Factors / chemistry
  • Peptide Termination Factors / physiology*
  • Protein Binding
  • Protein Structure, Tertiary
  • Saccharomyces cerevisiae Proteins / chemistry
  • Saccharomyces cerevisiae Proteins / metabolism
  • Saccharomyces cerevisiae Proteins / physiology*
  • Sequence Homology, Amino Acid
  • Zinc / chemistry
  • Zinc Fingers
  • tRNA Methyltransferases

Substances

  • Peptide Termination Factors
  • SUP45 protein, S cerevisiae
  • Saccharomyces cerevisiae Proteins
  • Glutamine
  • Nickel
  • Methyltransferases
  • tRNA Methyltransferases
  • Trm11 protein, S cerevisiae
  • Trm112 protein, S cerevisiae
  • Zinc

Associated data

  • PDB/2J6A