Structural and functional analysis of the nucleotide and DNA binding activities of the human PIF1 helicase

Dehghani-Tafti, Saba, Levdikov, Vladimir, Antson, Alfred A., Bax, Ben ORCID: https://orcid.org/0000-0003-1940-3785 and Sanders, Cyril M. 2019. Structural and functional analysis of the nucleotide and DNA binding activities of the human PIF1 helicase. Nucleic Acids Research 47 (6) , pp. 3208-3222. 10.1093/nar/gkz028

Preview

PDF - Published Version Available under License Creative Commons Attribution. Download (12MB) | Preview

Abstract

Pif1 is a multifunctional helicase and DNA processing enzyme that has roles in genome stability. The enzyme is conserved in eukaryotes and also found in some prokaryotes. The functions of human PIF1 (hPIF1) are also critical for survival of certain tumour cell lines during replication stress, making it an important target for cancer therapy. Crystal structures of hPIF1 presented here explore structural events along the chemical reaction coordinate of ATP hydrolysis at an unprecedented level of detail. The structures for the apo as well as the ground and transition states reveal conformational adjustments in defined protein segments that can trigger larger domain movements required for helicase action. Comparisons with the structures of yeast and bacterial Pif1 reveal a conserved ssDNA binding channel in hPIF1 that we show is critical for single-stranded DNA binding during unwinding, but not the binding of G quadruplex DNA. Mutational analysis suggests that while the ssDNA-binding channel is important for helicase activity, it is not used in DNA annealing. Structural differences, in particular in the DNA strand separation wedge region, highlight significant evolutionary divergence of the human PIF1 protein from bacterial and yeast orthologues.

Item Type:	Article
Date Type:	Publication
Status:	Published
Schools:	Biosciences
Additional Information:	This is an open access article distributed under the terms of the Creative Commons CC BY license, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Publisher:	Oxford University Press
ISSN:	0305-1048
Date of First Compliant Deposit:	31 January 2019
Date of Acceptance:	11 January 2019
Last Modified:	03 May 2023 14:53
URI:	https://orca.cardiff.ac.uk/id/eprint/119057

Citation Data

Cited 29 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item