title: A purine-pyrimidine motif verifying an identical presence in almost all gene taxonomic groups.
abstract: A statistical parameter identifies, with a high degree of significance, a motif which is present in protein-coding sequences of eukaryotes, prokaryotes, chloroplasts, mitochondria, viral introns, ribosomal RNA genes, and transfer RNA genes. The random probability of occurrence of such a situation is 10(-12). This motif has the following properties: (i) its significant presence in almost all present-day genes explains why it can be considered as primitive oligonucleotide, (ii) its nucleotide order is: YRY (N)6YRY, R being a purine base, Y a pyrimidine one and N any base, (iii) its length and its terminal trinucleotides YRY suggest a primordial function related to the spatial structure of the DNA sequences. This motif is found in some viral protein-coding genes, but not in eukaryotic introns.
authors.affiliation: I.U.T. de Belfort, Université de Franche-Comté, Belfort, France.
authors.forename: D G
authors.initials: DG
authors.lastname: Arquès
authors.forename: C J
authors.initials: CJ
authors.lastname: Michel
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000145:classification; D005796:Genes; D010802:Phylogeny; D011336:Probability; D011687:Purines; D011743:Pyrimidines
chemical_list: D011687:Purines; D011743:Pyrimidines; D004247:DNA