Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies

Bulky carcinogen-DNA adducts commonly cause replicative polymerases to stall, leading to a switch to bypass polymerases. We have investigated nucleotide incorporation opposite the major adduct of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the DinB family polymerase, Dpo4, using molecu...

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Main Authors: Zhang, Ling, Rechkoblit, Olga, Wang, Lihua, Patel, Dinshaw J., Shapiro, Robert, Broyde, Suse
Format: Online
Language:English
Published: Oxford University Press 2006
Online Access:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1500869/
id pubmed-1500869
recordtype oai_dc
spelling pubmed-15008692006-07-13 Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies Zhang, Ling Rechkoblit, Olga Wang, Lihua Patel, Dinshaw J. Shapiro, Robert Broyde, Suse Article Bulky carcinogen-DNA adducts commonly cause replicative polymerases to stall, leading to a switch to bypass polymerases. We have investigated nucleotide incorporation opposite the major adduct of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the DinB family polymerase, Dpo4, using molecular modeling and molecular dynamics (MD) simulations. PhIP, the most prevalent heterocyclic aromatic amine formed by cooking of proteinaceous food, is mutagenic in mammalian cells and is implicated in mammary and colon tumors. Our results show that the dG-C8-PhIP adduct can be accommodated in the spacious major groove Dpo4 open pocket, with Dpo4 capable of incorporating dCTP, dTTP or dATP opposite the adduct reasonably well. However, the PhIP ring system on the minor groove side would seriously disturb the active site, regardless of the presence and identity of dNTP. Furthermore, the simulations indicate that dATP and dTTP are better incorporated in the damaged system than in their respective mismatched but unmodified controls, suggesting that the PhIP adduct enhances incorporation of these mismatches. Finally, bulky C8-dG adducts, situated in the major groove, are likely to impede translocation in this polymerase (Rechkoblit et al. (2006), PLoS Biol., 4, e11). However, N2-dG adducts, which can reside on the minor groove side, appear to cause less hindrance when in this position. Oxford University Press 2006 2006-07-04 /pmc/articles/PMC1500869/ /pubmed/16820532 http://dx.doi.org/10.1093/nar/gkl425 Text en © 2006 The Author(s)
repository_type Open Access Journal
institution_category Foreign Institution
institution US National Center for Biotechnology Information
building NCBI PubMed
collection Online Access
language English
format Online
author Zhang, Ling
Rechkoblit, Olga
Wang, Lihua
Patel, Dinshaw J.
Shapiro, Robert
Broyde, Suse
spellingShingle Zhang, Ling
Rechkoblit, Olga
Wang, Lihua
Patel, Dinshaw J.
Shapiro, Robert
Broyde, Suse
Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies
author_facet Zhang, Ling
Rechkoblit, Olga
Wang, Lihua
Patel, Dinshaw J.
Shapiro, Robert
Broyde, Suse
author_sort Zhang, Ling
title Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies
title_short Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies
title_full Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies
title_fullStr Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies
title_full_unstemmed Mutagenic nucleotide incorporation and hindered translocation by a food carcinogen C8-dG adduct in Sulfolobus solfataricus P2 DNA polymerase IV (Dpo4): modeling and dynamics studies
title_sort mutagenic nucleotide incorporation and hindered translocation by a food carcinogen c8-dg adduct in sulfolobus solfataricus p2 dna polymerase iv (dpo4): modeling and dynamics studies
description Bulky carcinogen-DNA adducts commonly cause replicative polymerases to stall, leading to a switch to bypass polymerases. We have investigated nucleotide incorporation opposite the major adduct of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) in the DinB family polymerase, Dpo4, using molecular modeling and molecular dynamics (MD) simulations. PhIP, the most prevalent heterocyclic aromatic amine formed by cooking of proteinaceous food, is mutagenic in mammalian cells and is implicated in mammary and colon tumors. Our results show that the dG-C8-PhIP adduct can be accommodated in the spacious major groove Dpo4 open pocket, with Dpo4 capable of incorporating dCTP, dTTP or dATP opposite the adduct reasonably well. However, the PhIP ring system on the minor groove side would seriously disturb the active site, regardless of the presence and identity of dNTP. Furthermore, the simulations indicate that dATP and dTTP are better incorporated in the damaged system than in their respective mismatched but unmodified controls, suggesting that the PhIP adduct enhances incorporation of these mismatches. Finally, bulky C8-dG adducts, situated in the major groove, are likely to impede translocation in this polymerase (Rechkoblit et al. (2006), PLoS Biol., 4, e11). However, N2-dG adducts, which can reside on the minor groove side, appear to cause less hindrance when in this position.
publisher Oxford University Press
publishDate 2006
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1500869/
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