RT Journal Article SR Electronic T1 Structure of the helicase core of Werner helicase, a key target in microsatellite instability cancers JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202000795 DO 10.26508/lsa.202000795 VO 4 IS 1 A1 Joseph A Newman A1 Angeline E Gavard A1 Simone Lieb A1 Madhwesh C Ravichandran A1 Katja Hauer A1 Patrick Werni A1 Leonhard Geist A1 Jark Böttcher A1 John R Engen A1 Klaus Rumpel A1 Matthias Samwer A1 Mark Petronczki A1 Opher Gileadi YR 2021 UL https://www.life-science-alliance.org/content/4/1/e202000795.abstract AB Loss of WRN, a DNA repair helicase, was identified as a strong vulnerability of microsatellite instable (MSI) cancers, making WRN a promising drug target. We show that ATP binding and hydrolysis are required for genome integrity and viability of MSI cancer cells. We report a 2.2-Å crystal structure of the WRN helicase core (517–1,093), comprising the two helicase subdomains and winged helix domain but not the HRDC domain or nuclease domains. The structure highlights unusual features. First, an atypical mode of nucleotide binding that results in unusual relative positioning of the two helicase subdomains. Second, an additional β-hairpin in the second helicase subdomain and an unusual helical hairpin in the Zn2+ binding domain. Modelling of the WRN helicase in complex with DNA suggests roles for these features in the binding of alternative DNA structures. NMR analysis shows a weak interaction between the HRDC domain and the helicase core, indicating a possible biological role for this association. Together, this study will facilitate the structure-based development of inhibitors against WRN helicase.