title: Three-base periodicity patterns and self-similarity in whole bacterial chromosomes.
abstract: It has been reported that in a collection of mRNAs the triplets GhN or RNY had a higher propensity to be separated by either three/six/nine, etc., bases than by two/four/five, etc., bases. This has been called three-base periodicity (TBP). In this work the frequency distribution of distances (FDDs) for all triplets in the Borrelia burgdorferi chromosome and selected triplets in other model sequences were determined. The FDDs produced oscillatory decaying patterns with TBP for most triplets and not only for those encompassed by the above formulas. Furthermore, we also found TBP for di- and mononucleotides. However, TBP was not observed for intergenic regions, sequences with a low content of coding regions or when the coding potential of sequences was disrupted by base shuffling. Excluding closely related species the FDDs between bacterial genomes were different and appeared characteristic of the analyzed genome. FDDs also showed self-similarity, since 1Mb sequences rendered FDDs that were very similar to those for the entire sequence.
authors.affiliation: Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Apartado Postal 70228, CP 04510, México D.F., Mexico.
authors.forename: Imelda
authors.initials: I
authors.lastname: López-Villaseñor
authors.forename: Marco V
authors.initials: MV
authors.lastname: José
authors.forename: Joaquín
authors.initials: J
authors.lastname: Sánchez
mesh_terms: D001482:Base Composition; D001483:Base Sequence; D025065:Borrelia burgdorferi / Q000235:genetics*; D019847:Chromosomes, Archaeal / Q000235:genetics; D002876:Chromosomes, Bacterial / Q000235:genetics*; D003062:Codon / Q000235:genetics; D016680:Genome, Bacterial; D006801:Humans; D008957:Models, Genetic; D016366:Open Reading Frames / Q000235:genetics; D017422:Sequence Analysis, DNA / Q000379:methods; D016008:Statistical Distributions
chemical_list: D003062:Codon