Isolation of a class C transcription factor which forms a stable complex with tRNA genes

• Published in: The EMBO journal 1984-02, Vol.3 (2), p.343-350
• Main Authors: Ruet, A., Camier, S., Smagowicz, W., Sentenac, A., Fromageot, P.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; DNA Polymerase III; DNA-Directed RNA Polymerases - metabolism; Fundamental and applied biological sciences. Psychology; Genes, Fungal; Molecular and cellular biology; Molecular genetics; RNA polymerase III; RNA, Fungal - biosynthesis; RNA, Fungal - genetics; RNA, Transfer - biosynthesis; RNA, Transfer - genetics; Saccharomyces cerevisiae - analysis; Saccharomyces cerevisiae - genetics; transcription; Transcription Factors - isolation & purification; Transcription Factors - metabolism; Transcription, Genetic; Transcription. Transcription factor. Splicing. Rna processing; yeasts
• ISSN: 0261-4189; 1460-2075
• DOI: 10.1002/j.1460-2075.1984.tb01809.x

A yeast extract was fractionated to resolve the factors involved in the transcription of yeast tRNA genes. An in vitro transcription system was reconstituted with two separate protein fractions and purified RNA polymerase C (III). Optimal conditions for tRNA synthesis have been determined. One essential component, termed tau factor, was partially purified by conventional chromatographic methods on heparin‐agarose and DEAE‐Sephadex; it sedimented as a large macromolecule in glycerol gradients (mol. wt. approximately 300 000). tau factor was found to form a stable complex with the tRNA gene in the absence of other transcriptional components. Complex formation is very fast, is not temperature dependent between 10 degrees C and 25 degrees C and does not require divalent cations. The factor‐DNA complex is stable for at least 30 min at high salt concentration (0.1 M ammonium sulfate). These results indicate that gene recognition by a specific factor is a primary event in tRNA synthesis.