The cDNA for rat selenoprotein P contains 10 TGA codons in the open reading frame

K. E. Hill, R. S. Lloyd, J. G. Yang, R. Read, R. F. Burk

Research output: Contribution to journalArticlepeer-review

212 Scopus citations


Selenoprotein P is a plasma protein recently purified and characterized as containing 7.5 ± 1.0 selenium atoms/molecule as selenocysteine. In rats maintained on a defined diet containing nutritionally adequate amounts of selenate as the sole selenium source, over half the selenium in plasma is accounted for by selenoprotein P. Its cDNA has been cloned from a rat liver library and sequenced. The sequence is highly unusual, containing 10 TGA codons in its open reading frame prior to the TAA termination codon. TGA designates selenocysteine in other selenoproteins, and limited peptide sequencing that included the amino acids encoded by two of the TGA codons verified that they correspond to selenocysteine. The deduced 366-amino acid sequence is histidine- and cysteine-rich and contains 9 of its selenocysteines in the terminal 122 amino acids. Comparison of the deduced amino acid sequence of selenoprotein P with those of other selenoproteins reveals no significant similarities. Selenoprotein P represents a new class of selenoproteins and is the first protein described with more than 1 selenocysteine in a single polypeptide chain. The primary structure of selenoprotein P suggests that it might be responsible for some of the antioxidant properties of selenium.

Original languageEnglish (US)
Pages (from-to)10050-10053
Number of pages4
JournalJournal of Biological Chemistry
Issue number16
StatePublished - 1991
Externally publishedYes

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology


Dive into the research topics of 'The cDNA for rat selenoprotein P contains 10 TGA codons in the open reading frame'. Together they form a unique fingerprint.

Cite this