Dual roles of a multiprotein complex from S. cerevisiae in transcription and DNA repair.
Yeast RNA polymerase II initiation factor b, homolog of human TFIIH, is a protein kinase capable of phosphorylating the C-terminal repeat domain of the polymerase; it possesses a DNA-dependent ATPase activity as well. The 85 kd and 50 kd subunits of factor b are now identified as RAD3 and SSL1 proteins, respectively; both are known to be involved in DNA repair. Factor b interacts specifically with another DNA repair protein, SSL2. The ATPase activity of factor b may be due entirely to that associated with a helicase function of RAD3. Factor b transcriptional activity was unaffected, however, by amino acid substitution at a conserved residue in the RAD3 nucleotide-binding domain, suggesting that the ATPase/helicase function is not required for transcription. These results identify factor b as a core repairosome, which may be responsible for the preferential repair of actively transcribed genes in eukaryotes.
Feaver
W J
WJ
Department of Cell Biology, Stanford University School of Medicine, California 94305.
Svejstrup
J Q
JQ
Bardwell
L
L
Bardwell
A J
AJ
Buratowski
S
S
Gulyas
K D
KD
Donahue
T F
TF
Friedberg
E C
EC
Kornberg
R D
RD
D000251:Adenosine Triphosphatases / Q000502:physiology*; D001483:Base Sequence; D004265:DNA Helicases / Q000502:physiology*; D017931:DNA Primers / Q000737:chemistry; D004260:DNA Repair; D005656:Fungal Proteins / Q000502:physiology*; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D051758:Transcription Factor TFIIH; D014157:Transcription Factors / Q000737:chemistry / Q000502:physiology*; D014158:Transcription, Genetic
D017931:DNA Primers; D005656:Fungal Proteins; D046911:Macromolecular Substances; D046912:Multiprotein Complexes; C083908:SSL1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D051758:Transcription Factor TFIIH; D000251:Adenosine Triphosphatases; C061897:Rad3 protein, S cerevisiae; D004265:DNA Helicases