6o9m
From Proteopedia
Structure of the human apo TFIIH
Structural highlights
Disease[TF2H5_HUMAN] Defects in GTF2H5 are a cause of trichothiodystrophy photosensitive (TTDP) [MIM:601675]. TTDP is an autosomal recessive disease characterized by sulfur-deficient brittle hair and nails, ichthyosis, mental retardation, impaired sexual development, abnormal facies and cutaneous photosensitivity correlated with a nucleotide excision repair (NER) defect. Neonates with trichothiodystrophy and ichthyosis are usually born with a collodion membrane. The severity of the ichthyosis after the membrane is shed is variable, ranging from a mild to severe lamellar ichthyotic phenotype. There are no reports of skin cancer associated with TTDP. [ERCC3_HUMAN] IBIDS syndrome;Xeroderma pigmentosum complementation group B;PIBIDS syndrome;Xeroderma pigmentosum/Cockayne syndrome complex. Defects in ERCC3 are the cause of xeroderma pigmentosum complementation group B (XP-B) [MIM:610651]; also known as xeroderma pigmentosum II (XP2) or XP group B (XPB) or xeroderma pigmentosum group B combined with Cockayne syndrome (XP-B/CS). Xeroderma pigmentosum is an autosomal recessive pigmentary skin disorder characterized by solar hypersensitivity of the skin, high predisposition for developing cancers on areas exposed to sunlight and, in some cases, neurological abnormalities. Some XP-B patients present features of Cockayne syndrome, including dwarfism, sensorineural deafness, microcephaly, mental retardation, pigmentary retinopathy, ataxia, decreased nerve conduction velocities.[1] [2] Defects in ERCC3 are a cause of trichothiodystrophy photosensitive (TTDP) [MIM:601675]. TTDP is an autosomal recessive disease characterized by sulfur-deficient brittle hair and nails, ichthyosis, mental retardation, impaired sexual development, abnormal facies and cutaneous photosensitivity correlated with a nucleotide excision repair (NER) defect. Neonates with trichothiodystrophy and ichthyosis are usually born with a collodion membrane. The severity of the ichthyosis after the membrane is shed is variable, ranging from a mild to severe lamellar ichthyotic phenotype. There are no reports of skin cancer associated with TTDP.[3] [ERCC2_HUMAN] Trichothiodystrophy;COFS syndrome;Xeroderma pigmentosum complementation group D. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. The disease is caused by mutations affecting the gene represented in this entry. Function[TF2H5_HUMAN] Component of the TFIIH basal transcription factor involved in nucleotide excision repair (NER) of DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. Necessary for the stability of the TFIIH complex and for the presence of normal levels of TFIIH in the cell.[4] [TF2H4_HUMAN] Component of the core-TFIIH basal transcription factor involved in nucleotide excision repair (NER) of DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. [TF2H2_HUMAN] Component of the core-TFIIH basal transcription factor involved in nucleotide excision repair (NER) of DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. The N-terminus interacts with and regulates XPD whereas an intact C-terminus is required for a successful escape of RNAP II form the promoter. [TF2H1_HUMAN] Component of the core-TFIIH basal transcription factor involved in nucleotide excision repair (NER) of DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. [ERCC3_HUMAN] ATP-dependent 3'-5' DNA helicase, component of the core-TFIIH basal transcription factor, involved in nucleotide excision repair (NER) of DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. Acts by opening DNA either around the RNA transcription start site or the DNA damage.[5] [MAT1_HUMAN] Stabilizes the cyclin H-CDK7 complex to form a functional CDK-activating kinase (CAK) enzymatic complex. CAK activates the cyclin-associated kinases CDK1, CDK2, CDK4 and CDK6 by threonine phosphorylation. CAK complexed to the core-TFIIH basal transcription factor activates RNA polymerase II by serine phosphorylation of the repetitive C-terminus domain (CTD) of its large subunit (POLR2A), allowing its escape from the promoter and elongation of the transcripts. Involved in cell cycle control and in RNA transcription by RNA polymerase II.[6] [ERCC2_HUMAN] ATP-dependent 5'-3' DNA helicase, component of the core-TFIIH basal transcription factor. Involved in nucleotide excision repair (NER) of DNA by opening DNA around the damage, and in RNA transcription by RNA polymerase II by anchoring the CDK-activating kinase (CAK) complex, composed of CDK7, cyclin H and MAT1, to the core-TFIIH complex. Involved in the regulation of vitamin-D receptor activity. As part of the mitotic spindle-associated MMXD complex it plays a role in chromosome segregation. Might have a role in aging process and could play a causative role in the generation of skin cancers.[7] [8] [9] [10] [TF2H3_HUMAN] Component of the core-TFIIH basal transcription factor involved in nucleotide excision repair (NER) of DNA and, when complexed to CAK, in RNA transcription by RNA polymerase II. Anchors XPB. Publication Abstract from PubMedHuman transcription factor IIH (TFIIH) is part of the general transcriptional machinery required by RNA polymerase II for the initiation of eukaryotic gene transcription. Composed of ten subunits that add up to a molecular mass of about 500 kDa, TFIIH is also essential for nucleotide excision repair. The seven-subunit TFIIH core complex formed by XPB, XPD, p62, p52, p44, p34, and p8 is competent for DNA repair, while the CDK-activating kinase subcomplex, which includes the kinase activity of CDK7 as well as the cyclin H and MAT1 subunits, is additionally required for transcription initiation. Mutations in the TFIIH subunits XPB, XPD, and p8 lead to severe premature ageing and cancer propensity in the genetic diseases xeroderma pigmentosum, Cockayne syndrome, and trichothiodystrophy, highlighting the importance of TFIIH for cellular physiology. Here we present the cryo-electron microscopy structure of human TFIIH at 4.4 A resolution. The structure reveals the molecular architecture of the TFIIH core complex, the detailed structures of its constituent XPB and XPD ATPases, and how the core and kinase subcomplexes of TFIIH are connected. Additionally, our structure provides insight into the conformational dynamics of TFIIH and the regulation of its activity. The cryo-electron microscopy structure of human transcription factor IIH.,Greber BJ, Nguyen THD, Fang J, Afonine PV, Adams PD, Nogales E Nature. 2017 Sep 21;549(7672):414-417. doi: 10.1038/nature23903. Epub 2017 Sep, 13. PMID:28902838[11] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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