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Molecular dynamics simulations of B‐DNA: An analysis of the role of initial molecular configuration, randomly assigned velocity distribution, long integration times, and nonconstrained termini
Author(s) -
Falsafi Sassan,
Reich Norbert O.
Publication year - 1993
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360330312
Subject(s) - molecular dynamics , dodecameric protein , chemistry , dna , base pair , molecule , nanosecond , crystallography , molecular physics , chemical physics , computational chemistry , physics , optics , laser , biochemistry , organic chemistry
Molecular dynamics simulations of three DNA sequences using the AMBER 3.0 force field were performed with implicit inclusion of water through a distance‐dependent dielectric constant and solvated counterions. Simulations of the self‐complementary DNA dodecamer d(CGCGAATTCGCG) were started from a regular B‐DNA structure and the x‐ray single crystal B‐DNA structure. Although mean convergence during the 89‐ps calculation was confirmed, localized differences in backbone torsionals and base‐pair helicoidals were observed. A nanosecond simulation of the nonself‐complementary 14 base‐pair DNA d(GGCGGAATTGGCGG) indicates that most structural parameters stabilize within the first 100–200 ps, while isolated features show low‐frequency oscillations throughout the calculation. The lack of harmonic constraints on the ends of the molecules was shown not to perturb the structural dynamics of the internal oligonucleotide beyond the external 2 base pairs. Comparison of three simulations of the nonself‐complementary 14 base‐pair DNA d(GGCGAAATTCGCGG), identical in all respects other than the assignment of initial Maxwellian atomic velocity distributions, revealed the inherent systematic variability. The three calculations result in nearly superimposable global structures, with localized variations in torsionals and helicoidals. Our results provide a basis for performing a comparative analysis of the effect of DNA sequence on localized structure. © 1993 John Wiley & Sons, Inc.