General Introduction.- Contributors.- Section I. DNA Replication and Recombination.- 1 Enzymes of DNA Precursor Synthesis and the Control of DNA Replication.- 2 Replication Fork Propagation in Escherichia coli.- 3 The Role of RecA Protein in Homologous Genetic Recombination.- 4 The SV40 Large Tumor Antigen.- 5 Replication of the Human Immunodeficiency Virus.- Section II. Gene Transcription.- 6 Escherichia coli Repressor Proteins.- 7 Eukaryotic RNA Polymerases.- 8 Applications of Monoclonal Antibodies to the Study of Eukaryotic RNA Polymerases.- 9 RNA Polymerase III and Transcription of 5S Ribosomal DNA.- 10 Structure and Function of Rho Factor and Its Role in Transcription Termination.- 11 The Mechanism and Control of Pre-mRNA Splicing.- 12 Ribonucleoproteins and the Structure of Nascent Transcripts.- Section III. Chromosome Organization.- 13 Spatial Distribution of Chromosomes in Human Mitotic Cells.- 14 Structure/Function Relationships in the Bacteriophage T4 Single-Stranded DNA-Binding Protein.- 15 Crystallographic Studies of Two Proteins That Bind Single-Stranded DNA.- 16 Histone and Nucleosome Function in Yeast.- 17 Mammalian Protamines Structure and Molecular Interactions.- 18 Molecular Biology of Structural Chromosomal Proteins of the Mammalian Testis.

Chromosomes have structure, determined by the interactions of proteins with DNA, and chromosomes have functions, in particular, replication of DNA and transcription of messenger RNA. Chromosome structure and function are not separate topics, since chromosome organization pro foundly influences the activity of the genome in replication and transcrip tion. This is especially clear for higher cells, including human cells, in which chromatin fibers are created by the binding of histone proteins to the DNA, and folding of the fibers produces mitotic chromosomes and interphase nuclei. The intricate organization of DNA in higher cells is now recognized as being closely involved with genome activity. Many fundamental results have originated from studies of bacterial and viral systems, which have been systems of choice because of their less complex life cycles. The processes of replication and transcription show differences between the higher and simpler systems (e. g. , different enzymes and protein factors are involved). But the parallels are as striking as the differences in detail. Even for bacteria and viruses, a full understanding of these processes will require integrating the results of molecular biology with those of structural biology and cell biology. Three important subjects are covered in this volume: DNA replication and recombination, gene transcription, and chromosome organization. The sections dealing with replication and transcription examine recent results obtained by applying the techniques of molecular biology and biochemistry. Eukaryotic, prokaryotic, and viral systems are discussed.