A pre-catalytic non-covalent step governs DNA polymerase β fidelity
AuthorAlnajjar, Khadijeh S
Krylov, Ivan S
Kashemirov, Boris A
McKenna, Charles E
Goodman, Myron F
Sweasy, Joann B
AffiliationUniv Arizona, Canc Ctr,
Univ Arizona, Dept Cellular & Mol Med
MetadataShow full item record
PublisherOXFORD UNIV PRESS
CitationKhadijeh S Alnajjar, Ivan S Krylov, Amirsoheil Negahbani, Pouya Haratipour, Boris A Kashemirov, Ji Huang, Mariam Mahmoud, Charles E McKenna, Myron F Goodman, Joann B Sweasy, A pre-catalytic non-covalent step governs DNA polymerase β fidelity, Nucleic Acids Research, Volume 47, Issue 22, 16 December 2019, Pages 11839–11849, https://doi.org/10.1093/nar/gkz1076
JournalNUCLEIC ACIDS RESEARCH
RightsCopyright © The Author(s) 2019. Published by Oxford University Press on behalf of Nucleic Acids Research. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractDNA polymerase beta (pol beta) selects the correct deoxyribonucleoside triphosphate for incorporation into the DNA polymer. Mistakes made by pol beta lead to mutations, some of which occur within specific sequence contexts to generate mutation hotspots. The adenomatous polyposis coli (APC) gene is mutated within specific sequence contexts in colorectal carcinomas but the underlying mechanism is not fully understood. In previous work, we demonstrated that a somatic colon cancer variant of pol beta, K289M, misincorporates deoxynucleotides at significantly increased frequencies over wild-type pol beta within a mutation hotspot that is present several times within the APC gene. Kinetic studies provide evidence that the rate-determining step of pol beta catalysis is phosphodiester bond formation and suggest that substrate selection is governed at this step. Remarkably, we show that, unlike WT, a pre-catalytic step in the K289M pol beta kinetic pathway becomes slower than phosphodiester bond formation with the APC DNA sequence but not with a different DNA substrate. Based on our studies, we propose that precatalytic conformational changes are of critical importance for DNA polymerase fidelity within specific DNA sequence contexts.
NoteOpen access journal
VersionFinal published version