Table of Contents

I. X-Ray Crystallographic Studies of Ribosomal Subunits1. Progress toward the Crystal Structure of a Bacterial 30S Ribosomal Subunit 2. Crystal Structure of the Large Ribosomal Subunit at 5-A Resolution3. Identification of Selected Ribosomal Components in Crystallographic Maps of Prokaryotic Ribosomal Subunits at Medium Resolution II. Functional States Mapped by Cryo-Electron Microscopy4. Visualization of the Translational Elongation Cycle by Cryo-Electron Microscopy 5. Cryo-Electron Microscopy of the Translational Apparatus: Experimental Evidence for the Paths of mRNA, tRNA, and the Polypeptide Chain 6. Studies of Elongation Factor G-Dependent tRNA Translocation by Three-Dimensional Cryo-Electron MicroscopyIII. Structures of Isolated Components7. Ribosomal Proteins and Their Structural Transitions on and off the Ribosome 8. Structures of Bacterial Ribosomal Proteins: High-Resolution Probes of the Architecture and Mechanism of the Ribosome 9. Structure and Evolution of 23S rRNA Binding Domain of Protein L2 10. How Ribosomal Proteins and rRNA Recognize One Another 11. RNA Tertiary Structure and Protein Recognition in an L11-RNA Complex 12. On the Structure of the Yeast Ribosomal Stalk IV. Ribosomal Modeling13. Studies on the Structure and Function of Ribosomes by Combined Use of Chemical Probing and X-Ray Crystallography 14. Three-Dimensional Organization of the Bacterial Ribosome and Its Subunits: Transition from Low-Resolution Models to High-Resolution Structures 15. A Functional Interpretation of the Cryo-Electron Microscopy Map of the 30S Ribosomal Subunit from Escherichia coli V. rRNA Modifications and Protein Signals16. Bacterial, Archaeal, and Organellar rRNA Pseudouridines and Methylated Nucleosides and Their Enzymes 17. Nucleotide Modifications of Eukaryotic rRNAs: the World of Small Nucleolar RNA Guides Revisited 18. Nuclear Import of Ribosomal Proteins: Evidence for a Novel Type of Nuclear Localization Signal VI. Probing of Functional Sites19. Probing Ribosomal Structure and Function: Analyses with rRNA and Protein Mutants 20. Reconstitution of the 50S Subunit with In Vitro-Transcribed 23S rRNA: a New Tool for Studying Peptidyltransferase 21. Modern Site-Directed Cross-Linking Approaches: Implication for Ribosome Structure and Functions 22. Chemical Cleavage as a Probe of Ribosomal Structure 23. Applying Photolabile Derivatives of Oligonucleotides To Probe the Peptidyltransferase Center 24. Folding of Nascent Peptides on Ribosomes VII. Factor-Mediated Steps in the Elongation Cycle25. Mechanisms of Partial Reactions of the Elongation Cycle Catalyzed by Elongation Factors Tu and G 26. Ribosomal Elongation Cycle 27. Ternary Complex of EF-Tu and Its Action on the Ribosome 28. Insights into the GTPase Mechanism of EF-Tu from Structural Studies 29. The States, Conformational Dynamics, and Fusidic Acid-Resistant Mutants of Elongation Factor G VIII. mRNA Decoding30. Poking a Hole in the Sanctity of the Triplet Code: Inferences for Framing 31. The Unbearable Lightness of Peptidyl-tRNA 32. tmRNA: a Case of Structural and Functional Mimicry on and off the Ribosome? IX. Functional Target Sites for Antibiotics and Ribotoxins33. Antibiotic Biosynthesis: Some Thoughts on "Why?" and "How?" 34. Aminoglycoside Antibiotics and Decoding 35. Macrolide Resistance Conferred by Alterations in the Ribosome Target Site 36. Antibiotics and the Peptidyltransferase Center 37. Structures and Properties of Ribotoxins 38. Structure and Function of the Sarcin/Ricin Domain X. Initiation, Termination, and Recycling39. Translation Initiation in Bacteria 40. Factor-Mediated Termination of Protein Synthesis: a Welcome Return to the Mainstream of Translation 41. rRNA Functional Sites and Structures for Peptide Chain Termination 42. Genetic Probes to Bacterial Release Factors: tRNA Mimicry Hypothesis and Beyond 43. Ribosome Recycling Factor: an Essential Factor for Protein Synthesis 44. Mechanism of Bacterial Translation Termination and Ribosome Recycling XI. In Conclusion45. Concluding Remarks for the Helsingor Ribosome Conference, 13 to 17 June 1999