The Role of XPB/Ssl2 dsDNA Translocase Processivity in Transcription Start-site Scanning.

ABSTRACT: The general transcription factor TFIIH contains three ATP-dependent catalytic activities. TFIIH functions in nucleotide excision repair primarily as a DNA helicase and in Pol II transcription initiation as a dsDNA translocase and protein kinase. During initiation, the XPB/Ssl2 subunit of TFIIH couples ATP hydrolysis to dsDNA translocation facilitating promoter opening and the kinase module phosphorylates Pol II to facilitate the transition to elongation. These functions are conserved between metazoans and yeast; however, yeast TFIIH also drives transcription start-site scanning in which Pol II scans downstream DNA to locate productive start-sites. The ten-subunit holo-TFIIH from S. cerevisiae has a processive dsDNA translocase activity required for scanning and a structural role in scannin

SUBMITTER: Tomko EJ 

PROVIDER: S-EPMC8327364 | biostudies-literature | 2021 Jul

REPOSITORIES: biostudies-literature