NMR studies of the exocyclic 1,N sub 6 -ethenodeoxyadenosine adduct (. epsilon. dA) opposite deoxyguanosine in a DNA duplex. epsilon. dA(syn)ter dot dG(anti) pairing at the lesion site

Journal Article · Mon Feb 18 23:00:00 EST 1991 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00221a015· OSTI ID:5510300

de los Santos, C; Kouchakdjian, M; Patel, D J ^[1]; Yarema, K; Basu, A; Essigmann, J ^[2]

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1. Columbia Univ., New York, NY (USA)
2. Massachusetts Inst. of Tech., Cambridge (USA)

Proton NMR studies are reported on the complementary d(C-A-T-G-G-G-T-A-C){center dot}d(G-T-A-C-{epsilon}A-C-A-T-G) nonanucleotide duplex (designated {epsilon}dA{center dot}dG 9-mer duplex), which contains the exocyclic adduct 1,N{sup 6}-ethenodeoxyadenosine positioned opposite deoxyguanosine in the center of the helix. The present study focuses on the alignment of dG5 and {epsilon}dA14 at the lesion site in the {epsilon}dA{center dot}dG 9-mer duplex at neutral pH. This alignment has been characterized by monitoring the NOEs originating from the NH1 proton of dG5 and the H2, H5, and H7/H8 protons of {epsilon}dA14 in the central d(G4-G5-G6){center dot}d(C13-{epsilon}A14-C15) trinucleotide segment of the {epsilon}dA{center dot}dG 9-mer duplex. These NOE patterns establish that {epsilon}dA14 adopts a syn glycosidic torsion angle that positions the exocyclic ring toward the major groove edge while all the other bases including dG5 adopt anti glycosidic torsion angles. In summary, the dG5(anti){center dot}{epsilon}dA14(syn) alignment is readily accommodated into the DNA helix without disruption of flanking dG4{center dot}dC15 and dG6{center dot}dC13 base pairs and may account for the incorporation of dG opposite {epsilon}dA during in vitro replication by DNA polymerase I.

• OSTI ID: 5510300
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 30:7; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADDUCTS
AROMATICS
AZAARENES
CARCINOGENESIS
DNA ADDUCTS
GUANOSINE
HETEROCYCLIC COMPOUNDS
MAGNETIC RESONANCE
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
NUCLEIC ACIDS
NUCLEOSIDES
NUCLEOTIDES
OLIGONUCLEOTIDES
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OVERHAUSER EFFECT
PATHOGENESIS
PURINES
RESONANCE
RIBOSIDES
STEREOCHEMISTRY