Stable loop in the crystal structure of the intercalated four-stranded cytosine-rich metazoan telomere

Journal Article · Tue Apr 25 04:00:00 EDT 1995 · Proceedings of the National Academy of Sciences of the United States of America

DOI:https://doi.org/10.1073/pnas.92.9.3874· OSTI ID:96325

Kang, C H; Lockshin, C; Rich, A ^[1]

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1. Massachusetts Institute of Technology, Cambridge, MA (United States); and others

In most metazoans, the telomeric cytosine-rich strand repeating sequence is d(TAACCC). The crystal structure of this sequence was solved to 1.9-{angstrom} resolution. Four strands associate via the cytosine-containing parts to form a four-stranded intercalated structure held together by C-C{sup +} hydrogen bonds. The base-paired strands are parallel to each other, and the two duplexes are intercalated into each other in opposite orientations. One TAA end forms a highly stabilized loop with the 5{prime} thymine Hoogsteen-base-paired to the third adenine. The 5{prime} end of this loop is in close proximity to the 3{prime} end of one of the other intercalated cytosine strands. Instead of being entirely in a DNA duplex, this structure suggests the possibility of an alternative conformation for the cytosine-rich telomere strands. 25 refs., 5 figs.

• Sponsoring Organization: USDOE
• OSTI ID: 96325
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America, Journal Name: Proceedings of the National Academy of Sciences of the United States of America Journal Issue: 9 Vol. 92; ISSN PNASA6; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
CHROMOSOMES
CRYSTAL STRUCTURE
DNA
MITOSIS
STRUCTURAL CHEMICAL ANALYSIS