The 3D-structure of the archaeal homolog of XPB has been solved by X-ray crystallography by Dr. John Tainer and his group at The Scripps Research Institute.[5]
The function of the XPB(ERCC3) protein in NER is to assist in unwinding the DNA double helix after damage is initially recognized. NER is a multi-step pathway that removes a wide range of different DNA damages that distort normal base pairing. Such damages include bulky chemical adducts, UV-induced pyrimidine dimers, and several forms of oxidative damage. Mutations in the XPB(ERCC3) gene can lead, in humans, to xeroderma pigmentosum (XP) or XP combined with Cockayne syndrome (XPCS).[6] Mutant XPB cells from individuals with the XPCS phenotype are sensitive to UV irradiation and acute oxidative stress.[7]
Potent, bioactive natural products like triptolide that inhibit mammalian transcription via inhibition of the XPB subunit of the general transcription factor TFIIH has been recently reported as a glucose conjugate for targeting hypoxic cancer cells with increased glucose transporter expression.[18]
^Yee A, Nichols MA, Wu L, Hall FL, Kobayashi R, Xiong Y (December 1995). "Molecular cloning of CDK7-associated human MAT1, a cyclin-dependent kinase-activating kinase (CAK) assembly factor". Cancer Res. 55 (24): 6058–62. PMID8521393.
^Drapkin R, Reardon JT, Ansari A, Huang JC, Zawel L, Ahn K, Sancar A, Reinberg D (April 1994). "Dual role of TFIIH in DNA excision repair and in transcription by RNA polymerase II". Nature. 368 (6473): 769–72. Bibcode:1994Natur.368..769D. doi:10.1038/368769a0. PMID8152490. S2CID4363484.
^Iyer N, Reagan MS, Wu KJ, Canagarajah B, Friedberg EC (February 1996). "Interactions involving the human RNA polymerase II transcription/nucleotide excision repair complex TFIIH, the nucleotide excision repair protein XPG, and Cockayne syndrome group B (CSB) protein". Biochemistry. 35 (7): 2157–67. doi:10.1021/bi9524124. PMID8652557.
Maruyama K, Sugano S (1994). "Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides". Gene. 138 (1–2): 171–4. doi:10.1016/0378-1119(94)90802-8. PMID8125298.
Drapkin R, Reardon JT, Ansari A, Huang JC, Zawel L, Ahn K, Sancar A, Reinberg D (1994). "Dual role of TFIIH in DNA excision repair and in transcription by RNA polymerase II". Nature. 368 (6473): 769–72. Bibcode:1994Natur.368..769D. doi:10.1038/368769a0. PMID8152490. S2CID4363484.
Scott RJ, Itin P, Kleijer WJ, Kolb K, Arlett C, Muller H (1993). "Xeroderma pigmentosum-Cockayne syndrome complex in two patients: absence of skin tumors despite severe deficiency of DNA excision repair". J. Am. Acad. Dermatol. 29 (5 Pt 2): 883–9. doi:10.1016/0190-9622(93)70263-S. PMID8408834.
Iyer N, Reagan MS, Wu KJ, Canagarajah B, Friedberg EC (1996). "Interactions involving the human RNA polymerase II transcription/nucleotide excision repair complex TFIIH, the nucleotide excision repair protein XPG, and Cockayne syndrome group B (CSB) protein". Biochemistry. 35 (7): 2157–2167. doi:10.1021/bi9524124. PMID8652557.
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction
Well, that’s interesting to know that Psilotum nudum are known as whisk ferns. Psilotum nudum is the commoner species of the two. While the P. flaccidum is a rare species and is found in the tropical islands. Both the species are usually epiphytic in habit and grow upon tree ferns. These species may also be terrestrial and grow in humus or in the crevices of the rocks.
View the detailed Guide of Psilotum nudum: Detailed Study Of Psilotum Nudum (Whisk Fern), Classification, Anatomy, Reproduction