The cisplatin-1,2-d(GpG) (Pt-GG) intrastrand cross-link is the predominant DNA lesion generated by cisplatin. Cisplatin has been shown to predominantly induce G to T mutations and Pt-GG permits significant misincorporation of dATP by human DNA polymerase β (polβ). In agreement, polβ overexpression, which is frequently observed in cancer cells, is linked to cisplatin resistance and a mutator phenotype. However, the structural basis for the misincorporation of dATP opposite Pt-GG is unknown. Here, we report the first structures of a DNA polymerase inaccurately bypassing Pt-GG. We solved two structures of polβ misincorporating dATP opposite the 5′-dG of Pt-GG in the presence of Mg2+ or Mn2+. The Mg2+-bound structure exhibits a sub-optimal conformation for catalysis, while the Mn2+-bound structure is in a catalytically more favorable semi-closed conformation. In both structures, dATP does not form a coplanar base pairing with Pt-GG. In the polβ active site, the syn-dATP opposite Pt-GG appears to be stabilized by protein templating and pi stacking interactions, which resembles the polβ-mediated dATP incorporation opposite an abasic site. Overall, our results suggest that the templating Pt-GG in the polβ active site behaves like an abasic site, promoting the insertion of dATP in a non-instructional manner.
Skip Nav Destination
Article navigation
March 2020
-
Cover Image
Cover Image
Native electrospray ionization mass spectrometry revealed coronaviral polyprotein processing by the viral protease and subsequent complex formation. For further information, see the article by Kirchel and colleagues (pp. 1009–1019) in this issue. The image was in parts created by Anne Rupprecht (Rostock, Germany) and compiled by Boris Krichel. Image provided by Charlotte Uetrecht.
Research Article|
March 06 2020
Structural insights into the promutagenic bypass of the major cisplatin-induced DNA lesion
Hala Ouzon-Shubeita;
Hala Ouzon-Shubeita
*
Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
Search for other works by this author on:
Caroline K. Vilas;
Caroline K. Vilas
*
Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
Search for other works by this author on:
Seongmin Lee
Division of Chemical Biology and Medicinal Chemistry, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, U.S.A
Correspondence: Seongmin Lee (SeongminLee@austin.utexas.edu)
Search for other works by this author on:
Publisher: Portland Press Ltd
Received:
December 09 2019
Revision Received:
February 05 2020
Accepted:
February 07 2020
Accepted Manuscript online:
February 10 2020
Online ISSN: 1470-8728
Print ISSN: 0264-6021
© 2020 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society
2020
Biochem J (2020) 477 (5): 937–951.
Article history
Received:
December 09 2019
Revision Received:
February 05 2020
Accepted:
February 07 2020
Accepted Manuscript online:
February 10 2020
Citation
Hala Ouzon-Shubeita, Caroline K. Vilas, Seongmin Lee; Structural insights into the promutagenic bypass of the major cisplatin-induced DNA lesion. Biochem J 13 March 2020; 477 (5): 937–951. doi: https://doi.org/10.1042/BCJ20190906
Download citation file:
Sign in
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Captcha Validation Error. Please try again.