Mechanism of DNA loading by the DNA repair helicase XPD

Diana Constantinescu-Aruxandei, Biljana Petrovic-Stojanovska, Carlos Penedo, Malcolm F White, James H Naismith

Research output: Contribution to journalArticlepeer-review

36 Citations (Scopus)

Abstract

The xeroderma pigmentosum group D (XPD) helicase is a component of the transcription factor IIH complex in eukaryotes and plays an essential role in DNA repair in the nucleotide excision repair pathway. XPD is a 5′ to 3′ helicase with an essential iron–sulfur cluster. Structural and biochemical studies of the monomeric archaeal XPD homologues have aided a mechanistic understanding of this important class of helicase, but several important questions remain open. In particular, the mechanism for DNA loading, which is assumed to require large protein conformational change, is not fully understood. Here, DNA binding by the archaeal XPD helicase from Thermoplasma acidophilum has been investigated using a combination of crystallography, cross-linking, modified substrates and biochemical assays. The data are consistent with an initial tight binding of ssDNA to helicase domain 2, followed by transient opening of the interface between the Arch and 4FeS domains, allowing access to a second binding site on helicase domain 1 that directs DNA through the pore. A crystal structure of XPD from Sulfolobus acidocaldiarius that lacks helicase domain 2 has an otherwise unperturbed structure, emphasizing the stability of the interface between the Arch and 4FeS domains in XPD.
Original languageEnglish
Pages (from-to)2806-2815
Number of pages10
JournalNucleic Acids Research
Volume44
Issue number6
Early online date20 Feb 2016
DOIs
Publication statusPublished - 7 Apr 2016

Fingerprint

Dive into the research topics of 'Mechanism of DNA loading by the DNA repair helicase XPD'. Together they form a unique fingerprint.

Cite this