title: Selenocysteyl-tRNA occurs in the diatom Thalassiosira and in the ciliate Tetrahymena.
abstract: Selenocysteyl-tRNAs that decode UGA were identified previously in animal and bacterial cells and the genes for these tRNAs have been shown to be widespread in animals and eubacteria. In the present study, we identify a selenocysteyl-tRNA that codes for UGA in Thalassiosira pseudonana, which is a diatom, and in Tetrahymena borealis, which is a ciliate. The fact that these very diverse unicellular organisms also contain a selenocysteyl-tRNA suggests that selenocysteine-containing proteins and the use of UGA as a codon for selenocysteine are widespread, if not ubiquitous, in nature.
authors.affiliation: Laboratory of Experimental Carcinogenesis, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892.
authors.forename: D L
authors.initials: DL
authors.lastname: Hatfield
authors.forename: B J
authors.initials: BJ
authors.lastname: Lee
authors.forename: N M
authors.initials: NM
authors.lastname: Price
authors.forename: T C
authors.initials: TC
authors.lastname: Stadtman
mesh_terms: D000818:Animals; D003062:Codon; D003545:Cysteine / Q000031:analogs & derivatives*; D004755:Enterobacteriaceae / Q000235:genetics; D056890:Eukaryota / Q000737:chemistry* / Q000235:genetics; D005658:Fungi / Q000235:genetics; D005815:Genetic Code; D016566:Organoselenium Compounds; D017279:Selenocysteine; D013045:Species Specificity; D013768:Tetrahymena / Q000737:chemistry* / Q000235:genetics
chemical_list: D003062:Codon; D016566:Organoselenium Compounds; D017279:Selenocysteine; D003545:Cysteine