The major, N2-dG adduct of (+)-anti-B[a]PDE shows a dramatically different mutagenic specificity (predominantly, G → a) in a 5'-CGT-3' sequence context

Rajiv Shukla, Tongming Liu, Nicholas Geacintov, Edward L. Loechler

Research output: Contribution to journalArticle

Abstract

Mutations induced by the (+)-anti diol epoxide of benzo[a]pyrene [(+)- anti-B[a]PDE] were described previously in the supF gene of the Escherichia coli plasmid pUB3 [Rodriguez et al. (1993) Biochemistry, 32. 1759]. (+)- anti-B[a]PDE induced a complex pattern of mutations, including insertions, deletions, frameshifts, as well as base substitution mutations, which for G:C base pairs alone included a significant fraction of G:C → T:A, A:T and C:G mutations. A variety of results suggest that most of these mutations arise from the major adduct [[+ta]-B[a]P-N2-dG), raising the question how can a single adduct induce different kinds of mutations? Our working hypothesis in this regard is that (1) an adduct can adopt multiple conformations; (2) different conformations cause different mutations; and (3) adduct conformation is controlled by various factors, such as DNA sequence context. To investigate what conformation is associated with what mutation, it is essential to find examples where [+ta]-B[a]P-N2-dG induces principally one kind of mutation as a prelude to the study in that same context of the conformation(s) potentially relevant to mutagenesis. Earlier work indicated that (+)-anti-B[a]PDE gave a preponderance of G → A mutations in a 5'-CGT-3 sequence context, and herein it is shown that these mutations are likely to be attributable to the major adduct, since in this same sequence context [+ta]-B[a]P-N2-dG studied site specifically also induces principally G → A mutations (~82%). Previously, [+ta]-B[a]P-N2-dG was shown to induce principally G → T mutations (~97%) in a 5'-TGC-3' sequence context. Thus, by simply altering its surrounding sequence context this adduct can give a preponderance of either G → A or G → T mutations. This is the most dramatic change in base substitution mutagenic specificity for an adduct described to date and illustrates that the qualitative pattern of mutagenesis by a bulky adduct can be remarkably diverse.

Original languageEnglish (US)
Pages (from-to)10256-10261
Number of pages6
JournalBiochemistry
Volume36
Issue number33
DOIs
StatePublished - Aug 19 1997

Fingerprint

Conformations
Mutation
Mutagenesis
Substitution reactions
Biochemistry
Benzo(a)pyrene
DNA sequences
Epoxy Compounds
Escherichia coli
Plasmids
Genes
benzo(a)pyrene N2-dG adduct
INDEL Mutation
Base Pairing

ASJC Scopus subject areas

  • Biochemistry

Cite this

The major, N2-dG adduct of (+)-anti-B[a]PDE shows a dramatically different mutagenic specificity (predominantly, G → a) in a 5'-CGT-3' sequence context. / Shukla, Rajiv; Liu, Tongming; Geacintov, Nicholas; Loechler, Edward L.

In: Biochemistry, Vol. 36, No. 33, 19.08.1997, p. 10256-10261.

Research output: Contribution to journalArticle

@article{685b9ee266a94894a8e4ce17ab540add,
title = "The major, N2-dG adduct of (+)-anti-B[a]PDE shows a dramatically different mutagenic specificity (predominantly, G → a) in a 5'-CGT-3' sequence context",
abstract = "Mutations induced by the (+)-anti diol epoxide of benzo[a]pyrene [(+)- anti-B[a]PDE] were described previously in the supF gene of the Escherichia coli plasmid pUB3 [Rodriguez et al. (1993) Biochemistry, 32. 1759]. (+)- anti-B[a]PDE induced a complex pattern of mutations, including insertions, deletions, frameshifts, as well as base substitution mutations, which for G:C base pairs alone included a significant fraction of G:C → T:A, A:T and C:G mutations. A variety of results suggest that most of these mutations arise from the major adduct [[+ta]-B[a]P-N2-dG), raising the question how can a single adduct induce different kinds of mutations? Our working hypothesis in this regard is that (1) an adduct can adopt multiple conformations; (2) different conformations cause different mutations; and (3) adduct conformation is controlled by various factors, such as DNA sequence context. To investigate what conformation is associated with what mutation, it is essential to find examples where [+ta]-B[a]P-N2-dG induces principally one kind of mutation as a prelude to the study in that same context of the conformation(s) potentially relevant to mutagenesis. Earlier work indicated that (+)-anti-B[a]PDE gave a preponderance of G → A mutations in a 5'-CGT-3 sequence context, and herein it is shown that these mutations are likely to be attributable to the major adduct, since in this same sequence context [+ta]-B[a]P-N2-dG studied site specifically also induces principally G → A mutations (~82{\%}). Previously, [+ta]-B[a]P-N2-dG was shown to induce principally G → T mutations (~97{\%}) in a 5'-TGC-3' sequence context. Thus, by simply altering its surrounding sequence context this adduct can give a preponderance of either G → A or G → T mutations. This is the most dramatic change in base substitution mutagenic specificity for an adduct described to date and illustrates that the qualitative pattern of mutagenesis by a bulky adduct can be remarkably diverse.",
author = "Rajiv Shukla and Tongming Liu and Nicholas Geacintov and Loechler, {Edward L.}",
year = "1997",
month = "8",
day = "19",
doi = "10.1021/bi970541+",
language = "English (US)",
volume = "36",
pages = "10256--10261",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "33",

}

TY - JOUR

T1 - The major, N2-dG adduct of (+)-anti-B[a]PDE shows a dramatically different mutagenic specificity (predominantly, G → a) in a 5'-CGT-3' sequence context

AU - Shukla, Rajiv

AU - Liu, Tongming

AU - Geacintov, Nicholas

AU - Loechler, Edward L.

PY - 1997/8/19

Y1 - 1997/8/19

N2 - Mutations induced by the (+)-anti diol epoxide of benzo[a]pyrene [(+)- anti-B[a]PDE] were described previously in the supF gene of the Escherichia coli plasmid pUB3 [Rodriguez et al. (1993) Biochemistry, 32. 1759]. (+)- anti-B[a]PDE induced a complex pattern of mutations, including insertions, deletions, frameshifts, as well as base substitution mutations, which for G:C base pairs alone included a significant fraction of G:C → T:A, A:T and C:G mutations. A variety of results suggest that most of these mutations arise from the major adduct [[+ta]-B[a]P-N2-dG), raising the question how can a single adduct induce different kinds of mutations? Our working hypothesis in this regard is that (1) an adduct can adopt multiple conformations; (2) different conformations cause different mutations; and (3) adduct conformation is controlled by various factors, such as DNA sequence context. To investigate what conformation is associated with what mutation, it is essential to find examples where [+ta]-B[a]P-N2-dG induces principally one kind of mutation as a prelude to the study in that same context of the conformation(s) potentially relevant to mutagenesis. Earlier work indicated that (+)-anti-B[a]PDE gave a preponderance of G → A mutations in a 5'-CGT-3 sequence context, and herein it is shown that these mutations are likely to be attributable to the major adduct, since in this same sequence context [+ta]-B[a]P-N2-dG studied site specifically also induces principally G → A mutations (~82%). Previously, [+ta]-B[a]P-N2-dG was shown to induce principally G → T mutations (~97%) in a 5'-TGC-3' sequence context. Thus, by simply altering its surrounding sequence context this adduct can give a preponderance of either G → A or G → T mutations. This is the most dramatic change in base substitution mutagenic specificity for an adduct described to date and illustrates that the qualitative pattern of mutagenesis by a bulky adduct can be remarkably diverse.

AB - Mutations induced by the (+)-anti diol epoxide of benzo[a]pyrene [(+)- anti-B[a]PDE] were described previously in the supF gene of the Escherichia coli plasmid pUB3 [Rodriguez et al. (1993) Biochemistry, 32. 1759]. (+)- anti-B[a]PDE induced a complex pattern of mutations, including insertions, deletions, frameshifts, as well as base substitution mutations, which for G:C base pairs alone included a significant fraction of G:C → T:A, A:T and C:G mutations. A variety of results suggest that most of these mutations arise from the major adduct [[+ta]-B[a]P-N2-dG), raising the question how can a single adduct induce different kinds of mutations? Our working hypothesis in this regard is that (1) an adduct can adopt multiple conformations; (2) different conformations cause different mutations; and (3) adduct conformation is controlled by various factors, such as DNA sequence context. To investigate what conformation is associated with what mutation, it is essential to find examples where [+ta]-B[a]P-N2-dG induces principally one kind of mutation as a prelude to the study in that same context of the conformation(s) potentially relevant to mutagenesis. Earlier work indicated that (+)-anti-B[a]PDE gave a preponderance of G → A mutations in a 5'-CGT-3 sequence context, and herein it is shown that these mutations are likely to be attributable to the major adduct, since in this same sequence context [+ta]-B[a]P-N2-dG studied site specifically also induces principally G → A mutations (~82%). Previously, [+ta]-B[a]P-N2-dG was shown to induce principally G → T mutations (~97%) in a 5'-TGC-3' sequence context. Thus, by simply altering its surrounding sequence context this adduct can give a preponderance of either G → A or G → T mutations. This is the most dramatic change in base substitution mutagenic specificity for an adduct described to date and illustrates that the qualitative pattern of mutagenesis by a bulky adduct can be remarkably diverse.

UR - http://www.scopus.com/inward/record.url?scp=0030610081&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030610081&partnerID=8YFLogxK

U2 - 10.1021/bi970541+

DO - 10.1021/bi970541+

M3 - Article

VL - 36

SP - 10256

EP - 10261

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 33

ER -