Bulletin of Mathematical Biology

, Volume 51, Issue 4, pp 417–432

The multiple codes of nucleotide sequences

  • E. N. Trifonov
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DOI: 10.1007/BF02460081

Cite this article as:
Trifonov, E.N. Bltn Mathcal Biology (1989) 51: 417. doi:10.1007/BF02460081

Abstract

Nucleotide sequences carry genetic information of many different kinds, not just instructions for protein synthesis (triplet code). Several codes of nucleotide sequences are discussed including: (1) the translation framing code, responsible for correct triplet counting by the ribosome during protein synthesis; (2) the chromatin code, which provides instructions on appropriate placement of nucleosomes along the DNA molecules and their spatial arrangement; (3) a putative loop code for single-stranded RNA-protein interactions. The codes are degenerate and corresponding messages are not only interspersed but actually overlap, so that some nucleotides belong to several messages simultaneously. Tandemly repeated sequences frequently considered as functionless “junk” are found to be grouped into certain classes of repeat unit lengths. This indicates some functional involvement of these sequences. A hypothesis is formulated according to which the tandem repeats are given the role of weak enhancer-silencers that modulate, in a copy number-dependent way, the expression of proximal genes. Fast amplification and elimination of the repeats provides an attractive mechanism of species adaptation to a rapidly changing environment.

Copyright information

© Society for Mathematical Biology 1989

Authors and Affiliations

  • E. N. Trifonov
    • 1
  1. 1.Department of Polymer ResearchThe Weizmann Institute of ScienceRehovotIsrael

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