title: The sequence flanking translational initiation site in protozoa.
abstract: Nucleotide sequences flanking the translational initiation site were compiled from protozoan nuclear genes and were compared in every protozoan group. The entire 5'-untranslated sequences were very rich in A- and T-residues, but poor in G- and C-residues in most protozoan genes except for the flagellated ones. The sequence AAAAATTTTTAAAATTTAAAATGANAT emerged as a consensus sequence flanking the initiation site in the major protozoan group, although the sequences upstream from -4 (four nucleotides upstream from the ATG codon) were divergent among ciliates, sarcodinians, and sporozoans. On the other hand, the consensus sequence for flagellates was revealed to be a simple feature. Only the nucleotide position -3 was occupied with a high frequency of A-residue, in other positions it appeared randomly. These facts suggest that the strong preference for A-residue at the position -3 is a universal feature in nuclear genes for all eukaryotes.
authors.affiliation: Department of Biology, Faculty of Science, Shizuoka University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamauchi
mesh_terms: D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D016054:DNA, Protozoan; D056890:Eukaryota / Q000235:genetics*; D008969:Molecular Sequence Data; D010442:Peptide Chain Initiation, Translational / Q000235:genetics*; D010961:Plasmodium / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D013768:Tetrahymena / Q000235:genetics
chemical_list: D016054:DNA, Protozoan