Hydrogen-bonded nucleic acids base pairs substantially contribute to the structure and stability of nucleic acids. The study presents reference ab initio structures and interaction energies of selected base pairs with binding energies ranging from -5 to -47 kcal/mol. The molecular structures are obtained using the RI-MP2 (resolution of identity MP2) method with extended cc-pVTZ basis set of ato...

Hydroxypyridone and pyridopurine homo- and hetero-base pairs have been investigated in the context of duplex GNA (glycol nucleic acid). Phosphoramidites for automated GNA solid phase synthesis were synthesized economically in a few steps starting from commercially available enantiopure glycidol. Similar to their behavior in DNA, the hydroxypyridone and pyridopurine homo-base pairs display a met...

In this study, a single-base change discrimination strategy was developed through enhanced DNA toehold exchange reaction on a chip surface. A DNA strand with single-base change (SNPs, insertion or deletion) at an arbitrary position was clearly discriminated with nucleic acid concentrations from 0.8 nM to 1 μM through this method.

Base bulges are features of nucleic acid structure where a duplex section is interrupted by one or more formally singlestranded bases on one strand that are unopposed by bases on the other strand. Base bulges are very common features of folded RNA structures, where they can present highly recognizable features for specific protein binding; a good example is the binding of the human immunodefici...

The unique properties of fluorine atom on nucleic acid backbone can offer stricking functional and structural features. In order to extend the biological applications L-type acid, we chemically incorporate fluoro-modification into 2′-position L-cytidine, obtain a series fluoro-modified L-DNAs/ L-RNAs. Our melting study indicates that 2′-fluoro-modification does not disrupt thermostabilities wil...

The natural bases of nucleic acids have a strong preference for one tautomer form, guaranteeing fidelity in their hydrogen bonding potential. However, base pairs observed in recent crystal structures of polymerases and ribosomes are best explained by an alternative base tautomer, leading to the formation of base pairs with Watson-Crick-like geometries. These observations set limits to geometric...

Retrovirus particles contain a small, basic protein, the nucleocapsid (NC) protein, that possesses 'nucleic acid chaperone' activity--that is, the NC protein can catalyze the rearrangement of a nucleic acid molecule into the conformation that has the maximal number of base pairs. The molecular mechanism that underlies this effect is not understood. Because the chaperone activity is apparently c...

We measured the helical repeats of a non-natural nucleic acid, locked nucleic acid (LNA), by incorporating LNA strands into the outer arms of a DNA double crossover (DX) molecule; atomic force microscopy (AFM) imaging of the two-dimensional (2D) arrays self-assembled from these DX molecules allows us to derive the helical repeat of the LNA/DNA hetero-duplex to be 13.2 +/- 0.9 base pairs per turn.

G-quadruplexes constitute a class of nucleic acid structures defined by stacked guanine tetrads (or G-tetrads) with guanine bases from neighboring tetrads stacking with one another within the G-tetrad core. Individual G-quadruplexes can also stack with one another at their G-tetrad interface leading to higher-order structures as observed in telomeric repeat-containing DNA and RNA. In this study...

In building and refining nucleic acid structures, it is often desirable to enforce particular base pairing and/or base stacking interactions. Energy-based modeling programs with classical molecular mechanics force fields do not lend themselves to the easy imposition of penalty terms corresponding to such restraints, because the requirement that two bases lie in or near the same plane (pairing) ...