title: Mechanism of the inhibition by RNA of the RNA polymerases of Histoplasma capsulatum.
abstract: 4 S RNA isolated from the dimorphic fungus Histoplasma capsulatum inhibited the DNA-dependent RNA polymerase activity of the yeast phase of this fungus. Inhibition was specific for initiation, and resulted from binding of the RNA to the enzyme. Among a variety of synthetic polynucleotides tested, only poly(G) and oligo(dG) were effective inhibitors, suggesting a role for guanines or guanine-rich sequences of RNA in the inhibition reaction.
mesh_terms: D012321:DNA-Directed RNA Polymerases / Q000037:antagonists & inhibitors* / Q000378:metabolism; D006658:Histoplasma / Q000201:enzymology*; D007700:Kinetics; D011131:Polyribonucleotides / Q000494:pharmacology; D011485:Protein Binding; D012313:RNA / Q000378:metabolism / Q000494:pharmacology*; D012318:RNA Polymerase I / Q000037:antagonists & inhibitors; D012319:RNA Polymerase II / Q000037:antagonists & inhibitors; D013698:Templates, Genetic
chemical_list: D011131:Polyribonucleotides; D012313:RNA; D012319:RNA Polymerase II; D012321:DNA-Directed RNA Polymerases; D012318:RNA Polymerase I