TRACTS: A program to map oligopurine.oligopyrimidine and other binary DNA tracts

Nucleic Acids Res. 2003 Jul 1;31(13):3682-5. doi: 10.1093/nar/gkg625.


A program to map the locations and frequencies of DNA tracts composed of only two bases ('Binary DNA') is described. The program, TRACTS (URL and/or is of interest because long tracts composed of only two bases are highly over-represented in most genomes. In eukaryotes, oligopurine.oligopyrimidine tracts ('R.Y tracts') are found in the highest excess. In prokaryotes, W tracts predominate (A,T 'rich'). A pre-program, ANEX, parses database annotation files of GenBank and EMBL, to produce a convenient one-line list of every gene (exon, intron) in a genome. The main unit lists and analyzes tracts of the three possible binary pairs (R.Y, K.M and S;W). As an example, the results of R.Y tract mapping of mammalian gene p53 is described.

MeSH terms

  • Base Composition
  • Base Sequence
  • DNA / chemistry
  • Genes, p53
  • Humans
  • Internet
  • Purines / analysis*
  • Pyrimidines / analysis*
  • Sequence Analysis, DNA / methods*
  • Software*
  • User-Computer Interface


  • Purines
  • Pyrimidines
  • DNA