Recognition of RNA polymerase II and transcription bubbles by XPG, CSB, and TFIIH: insights for transcription-coupled repair and Cockayne Syndrome.
Loss of a nonenzymatic function of XPG results in defective transcription-coupled repair (TCR), Cockayne syndrome (CS), and early death, but the molecular basis for these phenotypes is unknown. Mutation of CSB, CSA, or the TFIIH helicases XPB and XPD can also cause defective TCR and CS. We show that XPG interacts with elongating RNA polymerase II (RNAPII) in the cell and binds stalled RNAPII ternary complexes in vitro both independently and cooperatively with CSB. XPG binds transcription-sized DNA bubbles through two domains not required for incision and functionally interacts with CSB on these bubbles to stimulate its ATPase activity. Bound RNAPII blocks bubble incision by XPG, but an ATP hydrolysis-dependent process involving TFIIH creates access to the junction, allowing incision. Together, these results implicate coordinated recognition of stalled transcription by XPG and CSB in TCR initiation and suggest that TFIIH-dependent remodeling of stalled RNAPII without release may be sufficient to allow repair.
Sarker
Altaf H
AH
Life Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Mail Stop 74R157, Berkeley, California 94720, USA.
Tsutakawa
Susan E
SE
Kostek
Seth
S
Ng
Cliff
C
Shin
David S
DS
Peris
Marian
M
Campeau
Eric
E
Tainer
John A
JA
Nogales
Eva
E
Cooper
Priscilla K
PK
D000251:Adenosine Triphosphatases / Q000378:metabolism; D003057:Cockayne Syndrome / Q000235:genetics / Q000378:metabolism*; D018360:Crystallography, X-Ray; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004720:Endonucleases / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008958:Models, Molecular; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012319:RNA Polymerase II / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors; D051758:Transcription Factor TFIIH / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics / Q000502:physiology; D000099250:DNA Excision Repair Protein ERCC-5
D000251:Adenosine Triphosphatases; D004268:DNA-Binding Proteins; D004720:Endonucleases; D009687:Nuclear Proteins; D012319:RNA Polymerase II; D051758:Transcription Factor TFIIH; D014157:Transcription Factors; D000099250:DNA Excision Repair Protein ERCC-5