PCF4 encodes an RNA polymerase III transcription factor with homology to TFIIB

Alfredo López-De-León, Monett Librizzi, Karen Puglia, Ian M. Willis

Research output: Contribution to journalArticle

101 Scopus citations


A dominant mutation in the PCF4 gene of S. cerevisiae was isolated as a suppressor of a tRNA gene A block promoter mutation. In vitro studies indicate that PCF4 is a stoichiometrically-required RNA polymerase III (pol III) transcription initiation factor. We show that the PCF4-1 mutation increases the number of transcriptionally competent preinitiation complexes by affecting a limiting activity in yeast cell extracts that is squelched by excess TFIIIC. The PCF4 gene encodes a TFIIB homolog whose size, biochemical, and genetic properties are consistent with those of the 70 kd subunit of TFIIIB. The TFIIB homology of PCF4 suggests a means for determining the polymerase specificity of a gene.

Original languageEnglish (US)
Pages (from-to)211-220
Number of pages10
Issue number2
Publication statusPublished - Oct 16 1992


ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)

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