Main description:

Contemporary views on the structure and function of chromatin are presented and the history of the development of these ideas as well as the nature of the nucleic acid and protein components of chromatin are reviewed. The structure of chromatin is studied at several levels, and its modes of transcription and replication are analyzed. Chromatin provides researchers with a critical evaluation of current knowledge. It combines much information that has never before been assembled, and evaluates and interrelates it in a critical way. This has not been done before so that readers are not only provided with an overview, but with extensive references to the literature (there are about 2000 references in all).

Contents:

1. The First Hundred Years.- 2. Development of the Nucleosome Model for Chromatin Structure.- 3. The Structures of DNA.- Composition and Modification of Eukaryotic DNA.- Conformations of DNA in the Solid State.- Hydration of DNA.- DNA Molecules in Solution.- Bent or Curved DNA.- Transformations from the B Form to Other DNA Conformations in Solution.- Topology of DNA: Supercoils and Cruciforms.- 4. The Proteins of Chromatin. I. Histones.- Occurrence and Distribution.- Isolation and Separation of Histones.- The Primary Structures of Histones.- Histone Variants.- Histone Modifications.- Secondary and Tertiary Structure of Histones.- Histone-Histone Interactions.- Noneukaryotic Histone-Like Proteins and the Evolution of the Histones.- 5. The Proteins of Chromatin. II. Nonhistone Chromosomal Proteins.- Enzymes Associated with Chromatin.- Transcription-Regulating Proteins.- Hormone Receptors.- The High Mobility Group (HMG) Proteins.- Chromosomal Structural Proteins.- 6. The Nucleosome.- The Core Particle.- Organization of the Nucleosome Above the Core Particle Level.- Conformational Transitions of the Nucleosome.- 7. Higher-Order Structure.- Nucleosome Arrangement.- Higher-Order Structures: Chromatin Fibers.- Higher-Order Folding of the Chromatin Fiber: The Chromosome.- 8. Chromatin Structure and Transcription.- The Nature of the Problem.- Experimental Approaches.- Chromatin Fractionation.- The Chromatin Structure of Some Specific Genes.- A Role of DNA Methylation?.- Chromosomal Proteins and Gene Activity.- DNA Torsion and Transcription.- A Tentative Model for Gene Activation.- 9. Replication of Chromatin.- DNA Replication.- Histone Synthesis.- Nucleosome Assembly and Histone Distribution.- Nucleosome Segregation.- Nascent Chromatin and Its Maturation.- References.