457D

MOLECULAR AND CRYSTAL STRUCTURE OF D(CGCGMO6AATTCGCG): N6-METHOXYADENOSINE/ THYMIDINE BASE-PAIRS IN B-DNA

457D の概要

• エントリーDOI: 10.2210/pdb457d/pdb
• 分子名称: DNA (5'-D(*CP*GP*CP*GP*(A47)P*AP*TP*TP*CP*GP*CP*G)-3'), MAGNESIUM ION (3 entities in total)
• 機能のキーワード: modified nucleotide, methoxyadenosine, dna damage, b-dna, double helix, dna
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 7411.14

構造登録者

Chatake, T.,Ono, A.,Ueno, Y.,Matsuda, A.,Takenaka, A. (登録日: 1999-03-06, 公開日: 2000-01-01, 最終更新日: 2023-12-27)

主引用文献

Chatake, T.,Hikima, T.,Ono, A.,Ueno, Y.,Matsuda, A.,Takenaka, A.
Crystallographic studies on damaged DNAs. II. N(6)-methoxyadenine can present two alternate faces for Watson-Crick base-pairing, leading to pyrimidine transition mutagenesis.
J.Mol.Biol., 294:1223-1230, 1999

PubMed Abstract: In a previous paper, 2'-deoxy-N(6)-methoxyadenosine (mo(6)A) was shown to form a mismatch base-pair with 2'-deoxycytidine with a Watson-Crick-type geometry. To fully understand the structural basis of genetic mutations with damaged DNA, it is necessary to examine whether the methoxylated adenine residue still has the ability to form the regular Watson-Crick pairing with a thymine residue. Therefore, a DNA dodecamer with the sequence d(CGCGmo(6)AATTCGCG) has been synthesized and its crystal structure determined. The methoxylation has no significant effect on the overall DNA conformation, which is that of a standard B-form duplex. The methoxylated adenine moieties adopt the amino tautomer with an anti conformation around the C(6)-N(6) bond to the N(1) atom, and they form a Watson-Crick base-pair with thymine residues on the opposite strand, similar to an unmodified adenine residue. It is concluded that methoxylated adenine can present two alternate faces for base-pairing, thanks to the amino<-->imino tautomerism allowed by methoxylation. Based on this property, two gene transition routes are proposed.

PubMed: 10600380
DOI: 10.1006/jmbi.1999.3304

実験手法

X-RAY DIFFRACTION (2 Å)