Orientation of DNA on a surface from simulation.
DNA orientation near surfaces determines many properties related to hybridization efficiency. We performed a 40-ns molecular dynamics simulation to study the structure and orientation of a 12-base-pair DNA duplex tethered to a neutral, epoxide-coated silica surface. Starting with a canonical B-form tethered in an up-right position, normal to the surface, the DNA tilted to over 55 degrees and back. The time scale was a few nanoseconds for tilting events. The linker between the DNA and the surface went from standing upright to tilted, and finally collapsed on the surface. Although the DNA conformation fluctuated, it remained closed to B-form for the entire 40 ns. Calculations of helical parameters of the DNA show that the tethered end of the DNA changed its conformation noticeably when attracted to the surface.
Wong
Ka-Yiu
KY
Department of Chemistry and Institute for Molecular Design, University of Houston, 4800 Calhoun, Houston, TX 77204-5003, USA.
Pettitt
B Montgomery
BM
D003198:Computer Simulation; D004247:DNA / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D020411:Oligonucleotide Array Sequence Analysis; D013499:Surface Properties
D004247:DNA