In this paper, the preferred conformations of the bases with respect to the sugar in various base-sugar units are worked out using criteria of potential energy. The van der Waals type of intercations between nonbonded atoms is represented by a 6-12 function and the electrostatic interactions have be
Stereochemistry of nucleic acids and polynucleotides. VI. Minimum energy conformations of dimethyl phosphate
β Scribed by V. Sasisekharan; A. V. Lakshminarayanan
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1969
- Tongue
- English
- Weight
- 455 KB
- Volume
- 8
- Category
- Article
- ISSN
- 0006-3525
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β¦ Synopsis
As part of a study on the conformation of polynucleotides and nucleic acids the preferred conformations of the model conpound dimethyl phosphate are worked out using potential energy functions. In calculating the total potential energy associated with the conformation, nonbonded, torsional, and electrostatic terms have been considered. The variation of the total conformational energy is represented as a function of two torsion angles 4 and \ 1. which are the rotations about the two phosphoester bonds. The most stable conformations are found to be the gauche-gauche conformations about these bonds. The conformations observed for phosphodiesters in the solid state and in the proposed structures of polynucleotides and nucleic acids cluster around the minimum. Also, regions of minimum energy correspond well with the typical allowed regions of a representative dinucleotide.
π SIMILAR VOLUMES
The potential energy calculations on the sugar-phosphate unit for different puckerings of the sugar are reported in this paper. The results obtained here essentially confirm our earlier predictions made by using criteria of contact distances (hard-sphere potential) and are also supported by observed
In extension of the bicyclo-DNA nomenclature (see , Foornote 3), the name tricyclo-DNA and, correspondingly, tricyclo-deoxynucleosides was chosen to denominate this type of nucleotide and nucleoside analog. ## The numbering scheme as depicted in Fig. f for nucleosides was chosen in order to be ab