Nucleotides and nucleic acids; oligo- and poly-nucleotides
The synthesis of modified oligonucleotides is, as in previous years, divided into sections describing updates on synthesis, followed by modifications to the backbone, sugar and nucleobase. Modifications to the nucleobase continues to be the largest section with a broad range on nucleobase analogues described, whilst updates to oligonucleotide synthesis continue to decline due primarily to the fact that oligonucleotide synthesis is fully automated. The section on aptamers and aptazymes is a two year review, and, as in previous years, the number of publications in this field continues to grow. The range of aptamer targets ranges from small molecules, such as adenine, to aptamers that bind to cell surface proteins, the latter being particularly aimed at identifying cancer cells. The majority of publications in aptamers and aptazymes relate to uses as sensors, with a broad range of methods of detection of the aptamer target. The section described as oligonucleotide conjugates is again the largest section, with topics such as fluorophores that deal with a broad range of subjects including not only the different dyes that have been added to oligonucleotides but to the continually increasing area of single molecule studies. Another area that has seen continual growth is oligonucleotide nanostructures and nanodevices, where there have been many new publications concerning the number of different self-assembly structures and many more nanodevices, such as logic gates and mechanical systems described. Oligonucleotide structure determination has also continued to generate many publications, and in this volume the sections on X-ray crystallography and NMR are a review of the past two years. There have been a large number of complex structures reported describing oligonucleotide-protein interactions in particular, and this has not been confined to crystallography as advances in NMR studies allow solution structures of more complex systems. Finally there are a number of other methods used for the study of oligonucleotide systems, primarily using electron microscopy, but which also includes a number of other methods, such as atomic force spectroscopy, surface plasmon spectroscopy and Raman spectroscopy. All of these methodologies add to our understanding of oligonucleotides in living systems and in artificial constructs.