1gqu
From Proteopedia
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
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 Page seeded by OCA on Fri May 2 17:54:31 2008
