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
. 1985 Apr;7(3):141-51.
doi: 10.1007/BF02916536.

Substitution of selenocysteine for cysteine in a reticulocyte lysate protein synthesis system

E C Wilhelmsen  1 , W C Hawkes, A L Tappel
Affiliations

Substitution of selenocysteine for cysteine in a reticulocyte lysate protein synthesis system

E C Wilhelmsen et al. Biol Trace Elem Res. 1985 Apr.

Abstract

Selenocysteine occurs in the peptide backbone of several selenoenzymes. The mechanism, of selenocysteine incorporation has not been well characterized. The incorporation of selenocysteine into protein in a rabbit reticulocyte lysate (RRL) was studied at high levels of selenocysteine. [(75)Se]Selenocysteine incorporation was inhibited by cycloheximide and by nuclease treatment. Random RNA copolymers were tested for protein synthesis activity in the messenger RNA-dependent RRL system. Of the active polymers, poly CIU and GU most strongly stimulated the incorporation of selenocysteine. In a series of four polymers with different ratios of U to G, incorporation of selenocysteine and cysteine increased with increasing percentages of U, suggesting that selenocysteine and cysteine responded to the same codon, presumably UGU. Of the 20 protein amino acids, only cysteine and cystine competed with selenocysteine incorporation. Selenocysteine was charged to cysteine-accepting tRNA in RRL. These results show that at supraphysiological concentrations selenocysteine can substitute for cysteine in RRL protein synthesis. Misincorporation of selenocysteine could be important when animal tissues contain high levels of selenium.

PubMed Disclaimer

Similar articles

See all similar articles

References

    1. Biochem Biophys Res Commun. 1980 Apr 29;93(4):1181-8 - PubMed
    1. Cold Spring Harb Symp Quant Biol. 1966;31:705-14 - PubMed
    1. Biochem Biophys Res Commun. 1978 Sep 14;84(1):248-53 - PubMed
    1. Biochim Biophys Acta. 1982 Dec 20;709(2):304-9 - PubMed
    1. Science. 1973 Feb 9;179(4073):588-90 - PubMed
-