Nucleic Acid Structure and Recognition provides a detailed view of the molecular structures of DNA and RNA and how they are recognized by small molecules and proteins. Extensive source material is provided, including information on relevant web sites and computer programmes. The major methods of structural investigation for nucleic acids, X-ray crystallography, NMR, and molecular modelling, are reviewed and their limitations (in the context of nucleic acids) discussed. Also covered are : the conformational features of nucleic acid building blocks, including a description of how base-pair morphologies are analysed ; the structures of DNA double helices and helical oligonucleotides, emphasizing current ideas on sequence-dependent structure ; and DNA-DNA interactions, including triplexes and quadruplexes. The principles of RNA folding, ribosomes, and ribozyme structure are also surveyed. Both covalent and non-covalent interactions with small molecules are described, with the emphasis on recognition principles and sequence-specific gene recognition. The principles of protein-DNA recognition are also covered, focussing on regulatory proteins. Nucleic Acid Structure and Recognition will therefore equip readers with a good understanding of all the important aspects of this major field.