This book provides a detailed view of the molecular structures of DNA and RNA and how they are recognised 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 scope and 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, emphasising current ideas on sequence-dependent structure; and DNA-DNA interactions, including triplexes and quadruplexes. The principles of RNA folding, ribosome, and ribozyme structure are also surveyed. Both covalent and non-covalent nucleic acid interactions with small molecules are described, with the emphasis on recognition principles and sequence specific gene recognition. The principles of protein - nucleic acid are 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. The Nucleic Acid Database (NDB) crystallographic and NMR structures for the nucleic acid structures described in the book are freely available through the Nucleic Acid Structure and Recognition website.