What is the role of TFIIH in transcription?
TFIIH is a multifunctional complex composed of 10 subunits, with an essential role in transcription, in which it functions in promoter opening, RNA polymerase II (RNAPII) phosphorylation, and promoter escape; this along with a central role in NER by promoting damaged strand discrimination, DNA opening, and endonuclease …
Can DNA damage occur during transcription?
It is thus evident that DNA damage can have opposite effects on transcription. We presume that there must exist a mechanism that enables cells to distinguish between these “scheduled” DNA damage events linked to gene activation from those that arise spontaneously and cause undesirable consequences.
Which of the following is required for the initiation of transcription?
Explanation: The sigma factor is solely required for the initiation of transcription. In fact, the sigma subunit will often fall off of the enzyme during the elongation phase of transcription. Binding of the sigma factor is an important signal for transcription to begin.
What is the function of TFIIH in the transcription initiation complex chegg?
TFIIH has kinase activity and phosphorylates the tail of RNA polymerase, and this phosphorylation leads to the release of several transcription factors. b. TFIIH has helicase activity and unwinds short section of the DNA to allow RNA polymerase to bind, allowing transcription initiation. c.
What disease is caused by DNA deficiency?
Table 1
| Disease/Syndrome | Gene | Neurological |
|---|---|---|
| DNA DSB deficiency | ||
| Ataxia-telangiectasia | ATM | ataxia, neurodegeneration telangiectasia, dysarthria, |
| Ataxia-telangiectasia-like disorder | MRE11 | ataxia, neurodegeneration dysarthria, oculomotor apraxia |
| Nijmegen breakage syndrome | NBS1 | microcephaly |
What happens when errors occur during transcription?
However, errors that occur during transcription and translation can also have substantial effects on gene function by producing misfolded and malfunctioning proteins. Therefore, a single transcription error can result in many flawed proteins, whereas a translation error will disrupt only a single protein.
What happens when DNA transcription goes wrong?
Most of the mistakes during DNA replication are promptly corrected by DNA polymerase which proofreads the base that has just been added. In proofreading, the DNA pol reads the newly-added base before adding the next one so a correction can be made.
What happens during the initiation step of DNA transcription?
Initiation is the beginning of transcription. It occurs when the enzyme RNA polymerase binds to a region of a gene called the promoter. This signals the DNA to unwind so the enzyme can ”read” the bases in one of the DNA strands. The enzyme is now ready to make a strand of mRNA with a complementary sequence of bases.
How is the TFIIH involved in DNA repair?
TFIIH is a multiprotein complex that is involved in various cellular processes, including nucleotide excision repair (NER) and transcription, revealing the tight molecular connections between transcription and DNA repair.
What is the role of transcription initiation factor TFIIH?
The transcription initiation factor TFIIH is a remarkable protein complex that has a fundamental role in the transcription of protein-coding genes as well as during the DNA nucleotide excision repair pathway.
When does TFIIH enter the RNA polymerase II complex?
During the transcription, TFIIH enters the RNA polymerase II preinitiation complex and activates it prior to initiation. It may act in open complex formation and/or promoter clearance. In NER, TFIIH is recruited by XPA to the damaged sites (Park et al., 1995).
What is the role of XPB in TFIIH?
In 1993, Schaeffer and co-workers found that XPB, a subunit of TFIIH, is also a repair factor. In the same year, Kevin S. Sweder proposed that the ERCC3 has different roles in transcription initiation and NER. TFIIH, a nine-subunit protein complex, plays a dual role in both DNA excision repair and in transcription.