1EMQ

NMR OBSERVATION OF T-TETRADS IN A PARALLEL STRANDED DNA QUADRUPLEX FORMED BY SACCHAROMYCES CEREVISIAE TELOMERE REPEATS

Summary for 1EMQ

• Entry DOI: 10.2210/pdb1emq/pdb
• NMR Information: BMRB: 4609
• Descriptor: DNA (5'-D(*TP*GP*GP*TP*GP*GP*C)-3') (1 entity in total)
• Functional Keywords: t-tetrad, g-quadruplex, telomere, yeast, saccharomyces cerevisiae, dna
• Total number of polymer chains: 4
• Total formula weight: 8677.73

Authors

Hosur, R.V.,Patel, P.K. (deposition date: 2000-03-17, release date: 2000-04-04, Last modification date: 2024-05-22)

Primary citation

Patel, P.K.,Hosur, R.V.
NMR observation of T-tetrads in a parallel stranded DNA quadruplex formed by Saccharomyces cerevisiae telomere repeats.
Nucleic Acids Res., 27:2457-2464, 1999

PubMed Abstract: We report here the NMR structure of the DNA sequence d-TGGTGGC containing two repeats of Saccharomyces cerevisiae telomere DNA which is unique in that it has a single thymine in the repeat sequence and the number of Gs can vary from one to three. The structure is a novel quadruplex incor-porating T-tetrads formed by symmetrical pairing of four Ts via O4-H3 H-bonds in a plane. This is in contrast to the previous results on other telomeric sequences which contained more than one T in the repeat sequences and they were seen mostly in the flexible regions of the structures. We observed that the T4-tetrad was nicely accommodated in the center of the G-quadruplex, but it caused a small underwinding of the right handed helix. The T tetrad stacked well on the adjacent G3-tetrad, but poorly on the G5 tetrad. Likewise, T1 also formed a stable T-tetrad at the 5' end of the quadruplex. To our knowledge, this is the first report of T-tetrad formation in DNA structures. These observations are of significance from the points of view of both structural diversity and specific recognitions.

PubMed: 10352174
DOI: 10.1093/nar/27.12.2457

Experimental method

SOLUTION NMR