1U6N

Solution Structure of an Oligodeoxynucleotide Containing a Butadiene Derived N1 b-Hydroxyalkyl Adduct on Deoxyinosine in the Human N-ras Codon 61 Sequence

Summary for 1U6N

• Entry DOI: 10.2210/pdb1u6n/pdb
• Related: 1U6O
• Descriptor: 5'-D(*CP*GP*GP*AP*CP*(2BD)P*AP*GP*AP*AP*G)-3', 5'-D(*CP*TP*TP*CP*TP*TP*GP*TP*CP*CP*G)-3' (2 entities in total)
• Functional Keywords: butadiene, deoxyinosine, ras61, dna
• Total number of polymer chains: 2
• Total formula weight: 6778.48

Authors

Scholdberg, T.A.,Merritt, W.K.,Dean, S.M.,Kowalcyzk, A.,Harris, T.M.,Harris, C.M.,Lloyd, R.S.,Stone, M.P. (deposition date: 2004-07-30, release date: 2004-08-10, Last modification date: 2024-05-22)

Primary citation

Scholdberg, T.A.,Merritt, W.K.,Dean, S.M.,Kowalcyzk, A.,Harris, C.M.,Harris, T.M.,Rizzo, C.J.,Lloyd, R.S.,Stone, M.P.
Structure of an Oligodeoxynucleotide Containing a Butadiene Oxide-Derived N1 Beta-Hydroxyalkyl Deoxyinosine Adduct in the Human N-ras Codon 61 Sequence.
Biochemistry, 44:3327-3337, 2005

PubMed Abstract: The solution structure of the N1-(1-hydroxy-3-buten-2(S)-yl)-2'-deoxyinosine adduct arising from the alkylation of adenine N1 by butadiene epoxide (BDO), followed by deamination to deoxyinosine, was determined, in the oligodeoxynucleotide d(CGGACXAGAAG).d(CTTCTCGTCCG). This oligodeoxynucleotide contained the BDO adduct at the second position of codon 61 of the human N-ras protooncogene, and was named the ras61 S-N1-BDO-(61,2) adduct. (1)H NMR revealed a weak C(5) H1' to X(6) H8 NOE, followed by an intense X(6) H8 to X(6) H1' NOE. Simultaneously, the X(6) H8 to X(6) H3' NOE was weak. The resonance arising from the T(17) imino proton was not observed. (1)H NOEs between the butadiene moiety and the DNA positioned the adduct in the major groove. Structural refinement based upon a total of 364 NOE-derived distance restraints yielded a structure in which the modified deoxyinosine was in the high syn conformation about the glycosyl bond, and T(17), the complementary nucleotide, was stacked into the helix, but not hydrogen bonded with the adducted inosine. The refined structure provided a plausible hypothesis as to why this N1 deoxyinosine adduct strongly coded for the incorporation of dCTP during trans lesion DNA replication, both in Escherichia coli [Rodriguez, D. A., Kowalczyk, A., Ward, J. B. J., Harris, C. M., Harris, T. M., and Lloyd, R. S. (2001) Environ. Mol. Mutagen. 38, 292-296], and in mammalian cells [Kanuri, M., Nechev, L. N., Tamura, P. J., Harris, C. M., Harris, T. M., and Lloyd, R. S. (2002) Chem. Res. Toxicol. 15, 1572-1580]. Rotation of the N1 deoxyinosine adduct into the high syn conformation may facilitate incorporation of dCTP via Hoogsteen-type templating with deoxyinosine, thus generating A-to-G mutations.

PubMed: 15736943
DOI: 10.1021/bi0482452

Experimental method

SOLUTION NMR