Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2009 Jul 7;106(27):11045-8.
doi: 10.1073/pnas.0905212106. Epub 2009 Jun 22.

Eukaryotic cytosolic and mitochondrial phenylalanyl-tRNA synthetases catalyze the charging of tRNA with the meta-tyrosine

Liron Klipcan  1 , Nina Moor, Naama Kessler, Mark G Safro
Affiliations

Eukaryotic cytosolic and mitochondrial phenylalanyl-tRNA synthetases catalyze the charging of tRNA with the meta-tyrosine

Liron Klipcan et al. Proc Natl Acad Sci U S A. .

Abstract

The accumulation of proteins damaged by reactive oxygen species (ROS), conventionally regarded as having pathological potentials, is associated with age-related diseases such as Alzheimer's, atherosclerosis, and cataractogenesis. Exposure of the aromatic amino acid phenylalanine to ROS-generating systems produces multiple isomers of tyrosine: m-tyrosine (m-Tyr), o-tyrosine (o-Tyr), and the standard p-tyrosine (Tyr). Previously it was demonstrated that exogenously supplied, oxidized amino acids could be incorporated into bacterial and eukaryotic proteins. It is, therefore, likely that in many cases, in vivo-damaged amino acids are available for de novo synthesis of proteins. Although the involvement of aminoacyl-tRNA synthetases in this process has been hypothesized, the specific pathway by which ROS-damaged amino acids are incorporated into proteins remains unclear. We provide herein evidence that mitochondrial and cytoplasmic phenylalanyl-tRNA synthetases (HsmtPheRS and HsctPheRS, respectively) catalyze direct attachment of m-Tyr to tRNA(Phe), thereby opening the way for delivery of the misacylated tRNA to the ribosome and incorporation of ROS-damaged amino acid into eukaryotic proteins. Crystal complexes of mitochondrial and bacterial PheRSs with m-Tyr reveal the net of highly specific interactions within the synthetic and editing sites.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Aminoacylation of tRNAPhe with cognate and noncognate amino acids and specific deacylation of mischarged product. (A) Aminoacylation of E. coli tRNAPhe transcript (1.2 μM) with Phe or m-Tyr by HsmtPheRS (210 nM) or TtPheRS (24 nM) analyzed by electrophoresis in 8% denaturing gel at acidic conditions (0.1 M Na-acetate, pH 5). (B) Specific deacylation of m-Tyr-tRNAPhe. E. coli tRNAPhe transcript (1.2 μM) was aminoacylated with Phe (25 μM), m-Tyr (125 μM), or Tyr (1 mM) by HsmtPheRS (250 nM in experiments with Phe and m-Tyr, or 500 nM in experiments with Tyr) for 5 min; then the reaction was continued after addition (shown by arrows) of TtPheRS (16 nM), EcPheRS (48 nM), or HsctPheRS (32 nM).
Fig. 2.
Fig. 2.
Cognate and noncognate amino acids at the PheRS active site. (A) The unbiased electron density maps of phenylalanine moiety from HsmtPheRS complexed with Phe-AMP [Protein Data Bank (PDB) ID code 3CMQ] (Left), l- tyrosine from complex structure with TtPheRS (PDB ID code 2AMC) (Center), and m-Tyr from complex structure with HsmtPheRS (Right). (B) The active-site structure and residues of HsmtPheRS crucial for m-Tyr recognition. X9 is the well-ordered water molecule observed in almost all PheRS complexes.
Fig. 3.
Fig. 3.
The fragment of TtPheRS structure: editing site with bound m-Tyr. Amino acid residues making direct contacts with the ligand are shown. The electron density map is contoured at 2.5 σ.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Ibba M, Soll D. Aminoacyl-tRNA synthesis. Annu Rev Biochem. 2000;69:617–650. - PubMed
    1. Jakubowski H. Accuracy of aminoacyl-tRNA synthetases: Proofreading of amino acids. In: Ibba M, Francklyn C, Cusack S, editors. Aminoacyl-tRNA Synthetases. Austin, TX: Landes Bioscience; 2005. pp. 384–396.
    1. Hendrickson TL, de Crecy-Lagard V, Schimmel P. Incorporation of nonnatural amino acids into proteins. Annu Rev Biochem. 2004;73:147–176. - PubMed
    1. Stadtman ER. Protein oxidation and aging. Science. 1992;257:1220–1224. - PubMed
    1. Dean RT, Fu S, Stocker R, Davies MJ. Biochemistry and pathology of radical-mediated protein oxidation. Biochem J. 1997;324:1–18. - PMC - PubMed

Publication types

LinkOut - more resources