Serine tRNA complementary to the nonuniversal serine codon CUG in Candida cylindracea: evolutionary implications.
AUTOR(ES)
Yokogawa, T
RESUMO
In the asporogenic yeast Candida cylindracea, the codon CUG is read as serine instead of leucine. This is an unusual instance in which the amino acid assignment of a codon deviates from the universal code. To infer the evolutionary process of this change, the tRNA with the anticodon sequence CAG, which is complementary to and thus responsible for translation of the codon CUG, has been identified. Indeed, this tRNA translates an in-frame CUG codon in a synthetic mRNA as serine in an in vitro translation system. The gene for the tRNA is interrupted by an intron in the anticodon loop. Sequence comparisons of the tRNA and its gene suggest that a single cytidine was inserted into the anticodon loop of the gene for tRNA(Ser)IGA during evolution to produce tRNA(Ser)CAG. The tRNA(Ser)CAG may be produced from its precursor molecule containing the cytidine insertion by splicing.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=49719Documentos Relacionados
- Characterization of serine and leucine tRNAs in an asporogenic yeast Candida cylindracea and evolutionary implications of genes for tRNA(Ser)CAG responsible for translation of a non-universal genetic code.
- Evolutionary Origin of Nonuniversal Cug(ser) Codon in Some Candida Species as Inferred from a Molecular Phylogeny
- Non-universal decoding of the leucine codon CUG in several Candida species.
- Genes coding for the selenocysteine-inserting tRNA species from Desulfomicrobium baculatum and Clostridium thermoaceticum: structural and evolutionary implications.
- The CUG codon is decoded in vivo as serine and not leucine in Candida albicans.