Periodic Sequence Patterns in Human Exons

We analyse the sequential structure of human exons and their flanking introns by hidden Markov models. Together, models of donor site regions, acceptor site regions and flanked internal exons, show that exons --- besides the reading frame --- hold a specific periodic pattern. The pattern, which has the consensus: non-T(A/T)G and a minimal periodicity of roughly 10 nucleotides, is not a consequence of the nucleotide statistics in the three codon positions, nor of the well known nucleosome positioning signal. We discuss the relation between the pattern and other known sequence elements responsible for the intrinsic bending or curvature of DNA. Keywords: DNA, sequential structure, periodicity, exon, intron, hidden Markov models. and Jet Propulsion Laboratory, Caltech. y and Department of Psychology, Stanford University. Introduction Besides specifying the choice and order of amino acids in proteins genetic material hold a multitude of additional signals playing an important role in ..