Genome-wide location analysis reveals a role for Sub1 in RNA polymerase III transcription

Human PC4 and the yeast ortholog Sub1 have multiple functions in RNA polymerase II transcription. Genome-wide mapping revealed that Sub1 is present on Pol III-transcribed genes. Sub1 was found to interact with components of the Pol III transcription system and to stimulate the initiation and reinitiation steps in a system reconstituted with all recombinant factors. Sub1 was required for optimal Pol III gene transcription in exponentially growing cells.