Dissociation of Two Polypeptide Chains from Yeast RNA Polymerase A

• Published in: Proceedings of the National Academy of Sciences - PNAS 1975-08, Vol.72 (8), p.3034-3038
• Main Authors: Huet, Janine, Buhler, Jean-Marie, Sentenac, Andre, Fromageot, Pierre
• Format: Article
• Language: English
• Subjects: Amanitins - pharmacology; Antibodies; Chromatography; DNA; DNA-Directed RNA Polymerases - analysis; DNA-Directed RNA Polymerases - immunology; DNA-Directed RNA Polymerases - metabolism; Electrophoresis; Enzyme Activation - drug effects; Enzymes; Gels; Macromolecular Substances; Magnesium - pharmacology; Manganese - pharmacology; Molecular Weight; Peptides - analysis; Precipitin Tests; Protein Binding; RNA; Saccharomyces cerevisiae - enzymology; Sodium; Sulfates; Templates, Genetic; Yeasts
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.72.8.3034

Yeast RNA polymerase A (RNA nucleotidyltransferase; nucleosidetriphosphate:RNA nucleotidyltransferase; EC 2.7.7.6) can be converted to a new form of enzyme, called RNA polymerase A*, which is lacking two polypeptide chains of 48,000 and 37,000 daltons. Apart from these two missing polypeptides the subunit structures of RNA polymerases A and A*are indistinguishable. RNA polymerase A*differs from the complete enzyme in its electrophoretic and chromatographic behavior, template requirements, and α -amanitin sensitivity. RNA polymerase A*transcribes the alternated copolymer d(A-T)nwith the same efficiency as RNA polymerase A but its specific activity is greatly reduced with native calf thymus DNA as template. The transcription of a variety of synthetic templates is also altered by removal of the two polypeptide chains. RNA polymerase A*is inhibited by high concentrations of α -amanitin (500 μ g/ml), whereas RNA polymerase A is comparatively less sensitive to the toxic peptide. The data are discussed in terms of possible roles of the two dissociable polypeptides.