Actions of the rifamycins.

INTRODUCTION............................................................ 290 ACTION ON BACTERIA.................................................... 291 General Effects of Rifamycins In Vivo and In Vitro.............................. 291 Interaction of Rifamycins with DNA-Dependent RNA Polymerase (EC 2.7.7.6.) ..... ... 291 Characterization of RNA polymerase......................................... 291 Various steps of the RNA polymerase reaction................................. 291 Structure of RNA polymerase............................................... 292 Which enzymatic step is inhibited by rifamycins?.............................. 292 Complex formation of rifamycins with RNA polymerase......................... 293 Resistance Against the Action of Rifamycins.................................... 293 Relationship Between the Chemical Structure and Biological Activity of the Various Rifamycin Derivatives....................................................... 295 Rifamycins as a Tool in Biochemical Studies.................................... 297 Mode of Interaction Between Rifamycins and Bacterial RNA Polymerase ..... ....... 297 Nature of the enzyme-rifamycin complex..................................... 297 Relation between rifamycin-enzyme complex and enzyme inhibition ...... ........... 297 ACTION ON EUKARYOTES................................................. 298 ANTIVIRAL ACTIVITIES .................................................... 299 Effects on Bacterial Viruses 299 Effects on Mammalian Viruses................................................ 300 Effects on DNA Viruses..................................................... 300 Effects on RNA Viruses..................................................... 301 Effects on Trachoma Agent................................................... 301 CLINICAL APPLICATIONS.................................................. 302 COMPOUNDS RELATED TO THE RIFAMYCINS ............................ 302 SUMMARY AND CONCLUSIONS........................................... 304 LITERATURE CITED........................................................ 304