Nanosecond Molecular Dynamics of Zipper-like DNA Duplex Structures Containing Sheared G·A Mismatch Pairs

2000 ◽  
Vol 122 (31) ◽  
pp. 7564-7572 ◽  
Author(s):  
Nad'a Špačková ◽  
Imre Berger ◽  
Jiří Šponer
Keyword(s):  
Molecular Dynamics ◽  
Dna Duplex

scholarly journals Molecular Dynamics Simulation of Homo-DNA: The Role of Crystal Packing in Duplex Conformation

Crystals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 532
Author(s):  
Jonathan H. Sheehan ◽  
Jarrod A. Smith ◽  
Pradeep S. Pallan ◽  
Terry P. Lybrand ◽  
Martin Egli
Keyword(s):  
Crystal Structure ◽  
Molecular Dynamics ◽  
Nucleic Acid ◽  
Base Pair ◽  
Crystal Packing ◽  
Md Simulations ◽  
Conformational Flexibility ◽  
Dynamics Simulation ◽  
Dna Duplex ◽  
Solution Studies

The (4′→6′)-linked DNA homolog 2′,3′-dideoxy-β-D-glucopyranosyl nucleic acid (dideoxy-glucose nucleic acid or homo-DNA) exhibits stable self-pairing of the Watson–Crick and reverse-Hoogsteen types, but does not cross-pair with DNA. Molecular modeling and NMR solution studies of homo-DNA duplexes pointed to a conformation that was nearly devoid of a twist and a stacking distance in excess of 4.5 Å. By contrast, the crystal structure of the homo-DNA octamer dd(CGAATTCG) revealed a right-handed duplex with average values for helical twist and rise of ca. 15° and 3.8 Å, respectively. Other key features of the structure were strongly inclined base-pair and backbone axes in the duplex with concomitant base-pair slide and cross-strand stacking, and the formation of a dimer across a crystallographic dyad with inter-duplex base swapping. To investigate the conformational flexibility of the homo-DNA duplex and a potential influence of lattice interactions on its geometry, we used molecular dynamics (MD) simulations of the crystallographically observed dimer of duplexes and an isolated duplex in the solution state. The dimer of duplexes showed limited conformational flexibility, and key parameters such as helical rise, twist, and base-pair slide exhibited only minor fluctuations. The single duplex was clearly more flexible by comparison and underwent partial unwinding, albeit without significant lengthening. Thus, base stacking was preserved in the isolated duplex and two adenosines extruded from the stack in the dimer of duplexes were reinserted into the duplex and pair with Ts in a Hoogsteen mode. Our results confirmed that efficient stacking in homo-DNA seen in the crystal structure of a dimer of duplexes was maintained in the separate duplex. Therefore, lattice interactions did not account for the different geometries of the homo-DNA duplex in the crystal and earlier models that resembled inclined ladders with large base-pair separations that precluded efficient stacking.

Investigation of changes in the arrangement of water molecules and salt ions surrounding different atoms of the DNA molecule during the melting process: a molecular dynamics simulation study

2015 ◽  
Vol 93 (3) ◽  
pp. 348-361 ◽  
Author(s):  
C. Izanloo
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Double Helix ◽  
Melting Process ◽  
Minor Groove ◽  
Dynamics Simulation ◽  
Transition Curve ◽  
Water Molecules ◽  
Major Groove ◽  
Dna Duplex

A molecular dynamics simulation was performed on a B-DNA duplex (CGCGAATTGCGC) at different temperatures. The DNA was immerged in a saltwater medium with 1 mol/L NaCl concentration. The arrangements of water molecules and cations around the different atoms of DNA on the melting pathway were investigated. Almost for all atoms of the DNA by double helix → single-stranded transition, the water molecules released from the DNA duplex and cations were close to single-stranded DNA, but this behavior was not clearly seen at melting temperatures. Therefore, release of water molecules and cations approaching the DNA by the increase of temperature does not have any effect on the sharpness of the transition curve. Most of the water molecules and cations were found to be around the negatively charged phosphate oxygen atoms. The number of water molecules released from the first shell hydration upon melting in the minor groove was higher than in the major groove, and intrusion of cations into the minor groove after melting was higher than into the major groove. The hydrations of imino protons were different from each other and were dependent on DNA bases.

Molecular Dynamics simulations of azanaphthoquinone annelated pyrrole derivatives as anticancer agent in DNA duplex

2012 ◽  
Vol 113 (4) ◽  
pp. 555-562
Author(s):  
Auradee Punkvang ◽  
Pornpan Pungpo ◽  
Pharit Kamsri ◽  
Dararat Kasamsri ◽  
Apinya Srisupan ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Anticancer Agent ◽  
Dna Duplex ◽  
Pyrrole Derivatives ◽  
Dynamics Simulations
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