A Single Deoxynucleoside Kinase Variant from Drosophila melanogaster Synthesizes Monophosphates of Nucleosides That Are Components of an Expanded Genetic System.

Deoxynucleoside kinase from D. melanogaster (DmdNK) has broad specificity; although it catalyzes the phosphorylation of natural pyrimidine more efficiently than natural purine nucleosides, it accepts all four 2'-deoxynucleosides and many analogues, using ATP as a phosphate donor to give the corresponding deoxynucleoside monophosphates. Here, we show that replacing a single amino acid (glutamine 81 by glutamate) in DmdNK creates a variant that also catalyzes the phosphorylation of nucleosides that form part of an artificially expanded genetic information system (AEGIS).

Expanded Genetic Alphabets: Managing Nucleotides That Lack Tautomeric, Protonated, or Deprotonated Versions Complementary to Natural Nucleotides.

2,4-Diaminopyrimidine (trivially K) and imidazo[1,2-a]-1,3,5-triazine-2(8H)-4(3H)-dione (trivially X) form a nucleobase pair with Watson-Crick geometry as part of an artificially expanded genetic information system (AEGIS). Neither K nor X can form a Watson-Crick pair with any natural nucleobase. Further, neither K nor X has an accessible tautomeric form or a protonated/deprotonated state that can form a Watson-Crick pair with any natural nucleobase.

Polymerase Interactions with Wobble Mismatches in Synthetic Genetic Systems and Their Evolutionary Implications.

In addition to completing the Watson-Crick nucleobase matching "concept" (big pairs with small, hydrogen bond donors pair with hydrogen bond acceptors), artificially expanded genetic information systems (AEGIS) also challenge DNA polymerases with a complete set of mismatches, including wobble mismatches. Here, we explore wobble mismatches with AEGIS with DNA polymerase 1 from Escherichia coli. Remarkably, we find that the polymerase tolerates an AEGIS:standard wobble that has the same geometry as the G:T wobble that polymerases have evolved to exclude but excludes a wobble geometry that polymerases have never encountered in natural history.

Formation of two homo-chromophoric H-aggregates in DNA-assembled alternating dye stacks.

The understanding and description of collectively excited multichromophores is of crucial importance for many areas of basic and applied research. DNA has been used for the construction of well-defined heterochromophoric stacks. Electronic coupling among non-adjacent chromophores of the same type leads to the co-existence of PDI and pyrene H-aggregates in hybrids composed of alternating chromophore stacks.

Long-distance electronic energy transfer in light-harvesting supramolecular polymers.

The efficient collection of solar energy relies on the design and construction of well-organized light-harvesting systems. Herein we report that supramolecular phenanthrene polymers doped with pyrene are effective collectors of light energy. The linear polymers are formed through the assembly of short amphiphilic oligomers in water.

Influence of perylenediimide-pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity.

Aromatic π-π stacking interactions are ubiquitous in nature, medicinal chemistry and materials sciences. They play a crucial role in the stacking of nucleobases, thus stabilising the DNA double helix. The following paper describes a series of chimeric DNA-polycyclic aromatic hydrocarbon (PAH) hybrids.