2MHX

Structure of Exocyclic R,R N6,N6-(2,3-Dihydroxy-1,4-butadiyl)-2'-Deoxyadenosine Adduct Induced by 1,2,3,4-Diepoxybutane in DNA

2MHX の概要

• エントリーDOI: 10.2210/pdb2mhx/pdb
• NMR情報: BMRB: 19659
• 分子名称: 5'-D(*CP*GP*GP*AP*CP*(RBD)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)
• 機能のキーワード: b-form dna, 11-mer, deb induced adduct, dhb-da adduct, n-ras codon 61 sequence, dna
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 6795.51

構造登録者

Kowal, E.A.,Seneviratne, U.,Wickramaratne, S.,Doherty, K.E.,Cao, X.,Tretyakova, N.,Stone, M.P. (登録日: 2013-12-05, 公開日: 2014-05-28, 最終更新日: 2024-05-01)

主引用文献

Kowal, E.A.,Seneviratne, U.,Wickramaratne, S.,Doherty, K.E.,Cao, X.,Tretyakova, N.,Stone, M.P.
Structures of Exocyclic R,R- and S,S-N(6),N(6)-(2,3-Dihydroxybutan-1,4-diyl)-2'-Deoxyadenosine Adducts Induced by 1,2,3,4-Diepoxybutane.
Chem.Res.Toxicol., 27:805-817, 2014

PubMed Abstract: 1,3-Butadiene (BD) is an industrial and environmental chemical present in urban air and cigarette smoke, and is classified as a human carcinogen. It is oxidized by cytochrome P450 to form 1,2,3,4-diepoxybutane (DEB); DEB bis-alkylates the N(6) position of adenine in DNA. Two enantiomers of bis-N(6)-dA adducts of DEB have been identified: R,R-N(6),N(6)-(2,3-dihydroxybutan-1,4-diyl)-2'-deoxyadenosine (R,R-DHB-dA), and S,S-N(6),N(6)-(2,3-dihydroxybutan-1,4-diyl)-2'-deoxyadenosine (S,S-DHB-dA) [ Seneviratne , U. , Antsypovich , S. , Dorr , D. Q. , Dissanayake , T. , Kotapati , S. , and Tretyakova , N. ( 2010 ) Chem. Res. Toxicol. 23 , 1556 -1567 ]. Herein, the R,R-DHB-dA and S,S-DHB-dA adducts have been incorporated into the 5'-d(C(1)G(2)G(3)A(4)C(5)X(6)A(7)G(8)A(9)A(10)G(11))-3':5'-d(C(12)T(13)T(14)C(15)T(16)T(17)G(18)T(19)C(20)C(21)G(22))-3' duplex [X(6) = R,R-DHB-dA (R(6)) or S,S-DHB-dA (S(6))]. The structures of the duplexes were determined by molecular dynamics calculations, which were restrained by experimental distances obtained from NMR data. Both the R,R- and S,S-DHB-dA adducts are positioned in the major groove of DNA. In both instances, the bulky 3,4-dihydroxypyrrolidine rings are accommodated by an out-of-plane rotation about the C6-N(6) bond of the bis-alkylated adenine. In both instances, the directionality of the dihydroxypyrrolidine ring is evidenced by the pattern of NOEs between the 3,4-dihydroxypyrrolidine protons and DNA. Also in both instances, the anti conformation of the glycosyl bond is maintained, which combined with the out-of-plane rotation about the C6-N(6) bond, allows the complementary thymine, T(17), to remain stacked within the duplex, and form one hydrogen bond with the modified base, between the imine nitrogen of the modified base and the T(17) N3H imino proton. The loss of the second Watson-Crick hydrogen bonding interaction at the lesion sites correlates with the lower thermal stabilities of the R,R- and S,S-DHB-dA duplexes, as compared to the corresponding unmodified duplex. The reduced base stacking at the adduct sites may also contribute to the thermal instability.

PubMed: 24741991
DOI: 10.1021/tx400472p

実験手法

SOLUTION NMR