Related Experiment Video
Updated: May 27, 2026
Atomic Force Microscopy Investigations of DNA Lesion Recognition in Nucleotide Excision Repair
Published on: May 24, 2017
Functional and structural studies of the nucleotide excision repair helicase XPD suggest a polarity for DNA
Jochen Kuper1, Stefanie C Wolski, Gudrun Michels
1Rudolf Virchow Center for Experimental Biomedicine, Institute for Structural Biology, University of Würzburg, Würzburg, Germany. jochen.kuper@virchow.uni-wuerzburg.de
Abstract:
The XPD protein is a vital subunit of the general transcription factor TFIIH which is not only involved in transcription but is also an essential component of the eukaryotic nucleotide excision DNA repair (NER) pathway. XPD is a superfamily-2 5'-3' helicase containing an iron-sulphur cluster. Its helicase activity is indispensable for NER and it plays a role in the damage verification process. Here, we report the first structure of XPD from Thermoplasma acidophilum (taXPD) in complex with a short DNA fragment, thus revealing the polarity of the translocated strand and providing insights into how the enzyme achieves its 5'-3' directionality. Accompanied by a detailed mutational and biochemical analysis of taXPD, we define the path of the translocated DNA strand through the protein and identify amino acids that are critical for protein function.
Related Concept Videos
01:08Nucleotide Excision Repair
01:38Nucleotide Excision Repair
Cells are regularly exposed to mutagens—factors in the environment that can damage DNA and generate mutations. UV radiation is one of the most common mutagens and is estimated to introduce a significant number of changes in DNA. These include bends or kinks in the structure, which can block DNA replication or transcription. If these errors are not fixed, the damage can cause mutations, which in turn can result in cancer or disease depending on which sequences are...
01:08Nucleotide Excision Repair
01:02Long-patch Base Excision Repair
02:31Homologous Recombination
02:10Translesion DNA Polymerases
TLS polymerases are found in all three domains of life - archaea, bacteria, and eukaryotes. Of the different classes of TLS polymerases, members of the Y family are fitted with specialized structures that...