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1gqu
From Proteopedia
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CRYSTAL STRUCTURE OF AN ALTERNATING A-T OLIGONUCLEOTIDE FRAGMENT WITH HOOGSTEEN BASE PAIRING
Overview
We report here an alternative double-helical structure of the DNA, molecule. It has been found in the d(ATA(Br)UAT) and d(ATATAT) sequences, by single-crystal x-ray crystallography. This sequence is found not only, in TATA boxes, but also in other regulatory regions of DNA. Bases of the, two antiparallel strands form Hoogsteen pairs, with adenines in the syn, conformation. The structure is related neither to those found in triple, helices nor to parallel DNA duplexes. Its conformational parameters are, very similar to those of duplex DNA in the B form. Both forms may coexist, under physiological conditions, although the Hoogsteen pairing greatly, influences the recognition sites on DNA. Our results demonstrate that an, alternative to the classical B-DNA double helix is possible.
About this Structure
1GQU is a Protein complex structure of sequences from [1]. Full crystallographic information is available from OCA.
Reference
Crystal structure of an antiparallel DNA fragment with Hoogsteen base pairing., Abrescia NG, Thompson A, Huynh-Dinh T, Subirana JA, Proc Natl Acad Sci U S A. 2002 Mar 5;99(5):2806-11. PMID:11880632
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