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1evm
From Proteopedia
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NMR OBSERVATION OF A-TETRAD
Overview
The structure of the telomeric DNA has been a subject of extensive investigation in recent years due to the realization that it has important functional roles to play in vivo and the observations that truncated telomeric sequences exhibit a great variety of 3D structures in aqueous solutions. In this context, we describe here NMR structural studies on two truncated human telomeric DNA sequences, d-AG(3)T and d-TAG(3)T in solutions containing K(+)ions. The G(3)stretches in both the oligonucleotides were seen to form parallel-stranded quadruplexes. However, the AG(3)segment as a whole, had different structural characteristics. The structure of d-AG(3)T revealed the formation of a novel A-tetrad, which was not seen in d-TAG(3)T. The A's in the tetrad had syn glycosidic conformation as opposed to the anti conformation of the G's in the G-tetrads. The A-tetrad stacked well over the adjacent G-tetrad and the twist angle at this step was smaller in d-AG(3)T than in d-TAG(3)T. These observations are expected to be significant from the point of view of structural diversity and recognition in telomeres.
About this Structure
1EVM is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
NMR studies on truncated sequences of human telomeric DNA: observation of a novel A-tetrad., Patel PK, Koti AS, Hosur RV, Nucleic Acids Res. 1999 Oct 1;27(19):3836-43. PMID:10481022
Page seeded by OCA on Thu Mar 20 11:00:50 2008
