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457d
From Proteopedia
OCA (Talk | contribs)
(New page: 200px<br /><applet load="457d" size="350" color="white" frame="true" align="right" spinBox="true" caption="457d, resolution 2.0Å" /> '''MOLECULAR AND CRYSTAL...)
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Revision as of 19:44, 29 January 2008
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MOLECULAR AND CRYSTAL STRUCTURE OF D(CGCGMO6AATTCGCG): N6-METHOXYADENOSINE/ THYMIDINE BASE-PAIRS IN B-DNA
Overview
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.
About this Structure
457D is a Protein complex structure of sequences from [1] with as ligand. Full crystallographic information is available from OCA.
Reference
Crystallographic studies on damaged DNAs. II. N(6)-methoxyadenine can present two alternate faces for Watson-Crick base-pairing, leading to pyrimidine transition mutagenesis., Chatake T, Hikima T, Ono A, Ueno Y, Matsuda A, Takenaka A, J Mol Biol. 1999 Dec 17;294(5):1223-30. PMID:10600380
Page seeded by OCA on Tue Jan 29 21:44:17 2008
Categories: Protein complex | Chatake, T. | Matsuda, A. | Ono, A. | Takenaka, A. | Ueno, Y. | MG | B-dna | Dna damage | Double helix | Methoxyadenosine | Modified nucleotide
