Observation of preferred direction melting in a lattice model of poly(dA-dC)·poly(dG-dT)

✍ Scribed by V. V. Prabhu; L. Young; E. W. Prohofsky

• Publisher: Wiley (John Wiley & Sons)
• Year: 1991
• Tongue: English
• Weight: 286 KB
• Volume: 31
• Category: Article
• ISSN: 0006-3525
• DOI: 10.1002/bip.360310308

✦ Synopsis

In the biologically significant process of DNA transcript ion, biologists observe that the information in the DNA polymer is transcribed in a preferential direction. This is referred to as the 5'-3' direction in the RNA strand. We model the DNA as a n infinite lattice, introduce a defect in one cell, and explore the growth of the defect to the neighboring cells with increase in temperature. We find that the propagation of the defect demonstrates a distinct directional character. The calculation is a modified selfconsistent phonon approach ( M S P A ) .

During transcription, when information on a given strand is to be copied, enzymes have to split the hydrogen bonds in a given part of the DNA polymer. Then the RNA grows along one strand of the DNA molecule. T h e growth of RNA is always along the 5'-3' direction.' This implies that the splitting of hydrogen bonds of the DNA polymer proceeds preferentially along one direction. We have tried to understand the origin of this observed directional effect in terms of a lattice model of the DNA.