General transcription factor IIH subunit 2 is a protein that in humans is encoded by the GTF2H2 gene. [5] [6]
This gene is part of a 500 kb inverted duplication on chromosome 5q13. This duplicated region contains at least four genes and repetitive elements which make it prone to rearrangements and deletions. The repetitiveness and complexity of the sequence have also caused difficulty in determining the organization of this genomic region. This gene is within the telomeric copy of the duplication. Deletion of this gene sometimes accompanies deletion of the neighboring SMN1 gene in spinal muscular atrophy (SMA) patients but it is unclear if deletion of this gene contributes to the SMA phenotype. This gene encodes the 44 kDa subunit of RNA polymerase II transcription initiation factor IIH which is involved in basal transcription and nucleotide excision repair. Transcript variants for this gene have been described, but their full length nature has not been determined. A second copy of this gene within the centromeric copy of the duplication has been described in the literature. It is reported to be different by either two or four base pairs; however, no sequence data is currently available for the centromeric copy of the gene. [6]
GTF2H2 has been shown to interact with GTF2H5, [7] [8] XPB [7] [9] and ERCC2. [8] [10]
Nucleotide excision repair is a DNA repair mechanism. DNA damage occurs constantly because of chemicals, radiation and other mutagens. Three excision repair pathways exist to repair single stranded DNA damage: Nucleotide excision repair (NER), base excision repair (BER), and DNA mismatch repair (MMR). While the BER pathway can recognize specific non-bulky lesions in DNA, it can correct only damaged bases that are removed by specific glycosylases. Similarly, the MMR pathway only targets mismatched Watson-Crick base pairs.
XPB is an ATP-dependent DNA helicase in humans that is a part of the TFIIH transcription factor complex.
ERCC2, or XPD is a protein involved in transcription-coupled nucleotide excision repair.
Transcription factor II H (TFIIH) is an important protein complex, having roles in transcription of various protein-coding genes and DNA nucleotide excision repair (NER) pathways. TFIIH first came to light in 1989 when general transcription factor-δ or basic transcription factor 2 was characterized as an indispensable transcription factor in vitro. This factor was also isolated from yeast and finally named TFIIH in 1992.
Eukaryotic transcription is the elaborate process that eukaryotic cells use to copy genetic information stored in DNA into units of transportable complementary RNA replica. Gene transcription occurs in both eukaryotic and prokaryotic cells. Unlike prokaryotic RNA polymerase that initiates the transcription of all different types of RNA, RNA polymerase in eukaryotes comes in three variations, each translating a different type of gene. A eukaryotic cell has a nucleus that separates the processes of transcription and translation. Eukaryotic transcription occurs within the nucleus where DNA is packaged into nucleosomes and higher order chromatin structures. The complexity of the eukaryotic genome necessitates a great variety and complexity of gene expression control.
CDK7 is a cyclin-dependent kinase shown to be not easily classified. CDK7 is both a CDK-activating kinase (CAK) and a component of the general transcription factor TFIIH.
Transcription factor II E (TFIIE) is one of several general transcription factors that make up the RNA polymerase II preinitiation complex. It is a tetramer of two alpha and two beta chains and interacts with TAF6/TAFII80, ATF7IP, and varicella-zoster virus IE63 protein.
Cyclin-dependent kinase 7, or cell division protein kinase 7, is an enzyme that in humans is encoded by the CDK7 gene.
DNA-directed RNA polymerase II subunit RPB4 is an enzyme that in humans is encoded by the POLR2D gene.
CDK-activating kinase assembly factor MAT1 is an enzyme that in humans is encoded by the MNAT1 gene.
Cyclin-H is a protein that in humans is encoded by the CCNH gene.
DNA excision repair protein ERCC-6 is a protein that in humans is encoded by the ERCC6 gene. The ERCC6 gene is located on the long arm of chromosome 10 at position 11.23.
General transcription factor IIH subunit 4 is a protein that in humans is encoded by the GTF2H4 gene.
Transcription factor IIIB 90 kDa subunit is a protein that in humans is encoded by the BRF1 gene.
DNA excision repair protein ERCC-8 is a protein that in humans is encoded by the ERCC8 gene.
General transcription factor IIH subunit 1 is a protein that in humans is encoded by the GTF2H1 gene.
MMS19 nucleotide excision repair protein homolog is a protein that in humans is encoded by the MMS19 gene.
General transcription factor IIH subunit 5 is a protein that in humans is encoded by the GTF2H5 gene.
RNA polymerase II holoenzyme is a form of eukaryotic RNA polymerase II that is recruited to the promoters of protein-coding genes in living cells. It consists of RNA polymerase II, a subset of general transcription factors, and regulatory proteins known as SRB proteins.
In molecular biology, this protein domain represents Tbf5 which stands for TTDA subunit of TFIIH basal transcription factor complex, and Rex1 a type of nucleotide excision repair (NER) proteins. Nucleotide excision repair is a major pathway for repairing UV light-induced DNA damage in most organisms. The function of this protein is to aid transcription.
This article incorporates text from the United States National Library of Medicine, which is in the public domain.