Barry Cohen
New Jersey Institute of Technology
Thursday, June 2, 2005
1131 Kemper Hall
3 :10-4:00 p.m.
Abstract:
Because the genetic code maps multiple codons to most amino acids, a typical target protein may be encoded by an exponentially large number of different, but synonymous mRNA sequences. Each such mRNA sequence tends to form a structure corresponding to its minimum free energy. Hence nature has wide latitude to select among mRNA sequences that are informationally equivalent but structurally and energentically divergent.
If the folding energy of mRNA has functional significance and is the subject of natural selection, naturally occurring mRNA sequences can be expected to have a skewed distribution of folding energy relative to randomly constructed sequences. Further, the property on which natural selection operates can be expected to correlate with the energy. In this work, we demonstrate that the folding energies of bacterial mRNA transcripts are skewed relative to randomly composed sequences, and that this skewing correlates with functional groups of genes.