1 Crystallization and Data Collection.- Crystallization of integral membrane proteins.- Crystallization of protein and nucleic acids: A survey of methods and importance of the purity of the macromolecules.- Synchrotron radiation and macromolecular crystallography.- Data collection.- 2 Phase Problem.- Density modification methods.- Anomalous scattering in macromolecular structure analysis.- Single molecule electron crystallography.- Structure analysis of bacteriorhodopsin by electron crystallography.- Neutron diffraction: contribution to high and low resolution crystallography.- 3 Graphics and Structure Analysis.- Electron density fitting with computer graphics: A review and a glimpse.- Computer grapnics in the study of macromolecular interactions.- Prediction of protein structure from amino acid sequence.- 4 Water and Dynamics.- X-ray analysis of polypeptide hormones at ? 1Å resolution: Anisotropic thermal motion and secondary structure of pancreatic polypeptide and deamino-oxytocin.- Water at biomolecule interfaces.- Tho water structure in 27n insulin crystals.- The structure of water around a macrocyclic receptor: A Monte Carlo study of the hydration of 18-crown-6 in different conformations.- Simulating protein dynamics in Solution : Bovine pancreatic trypsin inhibitor.- 5 Drug Design - Site Directed Mutagenesis.- Rational design of DNA minor groove-binding anti-tumor drugs.- Protein crystallography and drug design.- Enzyme mechanism : What X-ray crystallography can(not) tell us.- The role of separate domains and of individual ami no-acids in enzyme catalysis, studied by site-directed mutagenesis.- Selected and directed mutants of T4 phage lysozyme.- 6 Viruses.- The structure of a human common cold virus (rhinovirus 14) and its functional relations to other picornaviruses.- The structure of poliovirus at 2.9 Å Resolution: Crystallographic methods and biological implications.- The structure of cowpea mosaic virus at 3.5 Å Resolution.- Adenovirus architecture.- 7 Protein - Nucleic Acids.- A bacteriophage repressor/operator complex at 7 Å Resolution.- Refined structure of DNase I at 2 Å resolution and model for the interaction with DNA.- Ribonuclease A and T1 Comparable mechanisms of RNA cleavage with different active site geometries.- Structural studies of ECO RV endonuclease and of its complexes with short DNA fragments.- Errors in DNA helices: G.T. mismatches in the A, B and Z forms of DNA.- 8 Proteins.- Relation between functional loop regions and intron positions in ?/ß domains.- The three-dimensional structure of antibodies.- The 3-dimensional structures of influenza virus neurominidase and an antieurominidase Fab Fragment.- Periplasmic binding proteins : Structures and new understanding of protein-ligand interactions.- Crystal structure of thaumatin I, a sweet taste receptor binding protein.- Structures of pyruvoyl-dependent histidine decarboxylase and mutant-3 phrohistidine decarboxylase from lactobacillus 30A.- State of X-ray structure determination of ascorbate oxidase from green zucchini squash.- X-ray structure of the light-harvesting biliprotein C- phycocyanin from M. laminus.- The crystal structure of the photosynthetic reaction center from Rhodopseudomonas viridis.- Structure and function of some electron-transfer proteins and complexes Monoheme C-type and multiheme C3- cytochromes.- Author Index.