DNA Modeller: an interactive program for modelling stacks of DNA base pairs on a microcomputer

DNA Modeller is a microcomputer program for interactively manipulatingup to 20 bp in a DNA double helical arrangement. It calculatesthe van der Waals and electrostatic energies of base-base interactionsusing the AMBER potential, minimizes the energy with respectto the pair (buckle, propeller, opening, shear, stretch, stagger)and step (tilt, roll, twist, shift, slide, rise) parameters,calculates lengths of the canonical hydrogen bonds between thecomplementary bases, and calculates interatomic distances betweenthe successive base pairs. Input/output files are simple listsof the step and pair parameters or lists of the atom specifications(N1, C2, etc.) and their Cartesian coordinates (compatible withthe Desktop Molecular Modeller ^*.mol files). The program issupplied with a readbrk utility which transforms PDB/NDB tothe^*.mol format readable by DNA Modeller. The DNA crystal structuresdeposited in the PDB or NDB databases can thus be analyzed,and their bases visualized and interactively manipulated. Inaddition, DNA Modeller can calculate the base pair and stepgeometrical parameters and interaction energies. A plotter utilitycreates wire mono or stereo pictures of the bases. This programis designed for IBM-compatible computers working under DOS orcan run as a DOS application under MS Windows 3.x or Merge (SCOUnix DOS emulator).