The structure of the mouse glutathione peroxidase gene: the selenocysteine in the active site is encoded by the 'termination' codon, TGA

EMBO J. 1986 Jun;5(6):1221-7.

Abstract

Glutathione peroxidase (GSHPx) is an important selenium-containing enzyme which protects cells from peroxide damage and also has a role in leukotriene formation. We report the identification of a genomic recombinant as encoding the entire mouse GSHPx gene. Surprisingly, the selenocysteine in the active site of the enzyme is encoded by TGA: this has been confirmed by primer extension/dideoxy sequencing experiments using reticulocyte mRNA. The same site of transcription initiation is used in three tissues in which the GSHPx mRNA is expressed at high levels (erythroblast, liver and kidney). Like some other regulated 'house-keeping' genes, the GSHPx gene has Sp1 binding site consensus sequences but no 'ATA' and 'CAAT' consensus sequences upstream of the transcription initiation site. Moreover, there is a cluster of two Sp1 binding site consensus sequences and two SV40 core enhancer sequences in the 3' region of the gene, close to the previously mapped position of a DNase I-hypersensitive site found only in tissues expressing the GSHPx mRNA at high levels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Cell Line
  • Codon*
  • Cysteine / analogs & derivatives*
  • DNA Restriction Enzymes
  • Genes*
  • Glutathione Peroxidase / genetics*
  • Leukemia, Experimental / enzymology
  • Mice
  • Mice, Inbred BALB C
  • RNA, Messenger*
  • Reticulocytes / metabolism
  • Selenium*
  • Selenocysteine
  • Transcription, Genetic

Substances

  • Codon
  • RNA, Messenger
  • Selenocysteine
  • Glutathione Peroxidase
  • DNA Restriction Enzymes
  • Selenium
  • Cysteine

Associated data

  • GENBANK/X03920