Quasi-continuum models of twist-like and accordion-like low-frequency motions in DNA.
Formulae for calculating low-frequency twist-like and accordion-like modes of DNA molecules have been derived using a quasi-continuum model. The formulae can be employed in essentially all (viz. A, B, C, D, E, and Z) forms of DNA. Calculated results indicate that the experimentally observed low-frequency modes at 22 cm-1 for the A-form octanucleotide (d[CCCCGGGG]) and at 18 cm-1 for the B-form dodecanucleotide (d[CGCAA ATTTGCG]) may result from accordion-like motions, while those observed at 12 cm-1 and 15 cm-1 may result from combinations of twist-like oscillations excited in the intact segments of B- and A-DNA's, respectively. Frequency shifts in the low-frequency modes observed when DNA molecules undergo conformational changes among different forms are also discussed in terms of the current model.
Chou
K C
KC
Computational Chemistry, Upjohn Research Laboratories, Kalamazoo, Michigan 49001.
Maggiora
G M
GM
Mao
B
B
D004247:DNA; D008433:Mathematics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D009838:Oligodeoxyribonucleotides; D009991:Oscillometry
D009838:Oligodeoxyribonucleotides; D004247:DNA