We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.
In most metazoans, the telomeric cytosine-rich strand repeating sequence is d(TAACCC). The crystal structure of this sequence was solved to 1.9-A resolution. Four strands associate via the cytosine-containing parts to form a four-stranded intercalated structure held together by C.C+ 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' thymine Hoogsteen-base-paired to the third adenine. The 5' end of this loop is in close proximity to the 3' 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.
Stable loop in the crystal structure of the intercalated four-stranded cytosine-rich metazoan telomere.,Kang C, Berger I, Lockshin C, Ratliff R, Moyzis R, Rich A Proc Natl Acad Sci U S A. 1995 Apr 25;92(9):3874-8. PMID:7731999[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
↑ Kang C, Berger I, Lockshin C, Ratliff R, Moyzis R, Rich A. Stable loop in the crystal structure of the intercalated four-stranded cytosine-rich metazoan telomere. Proc Natl Acad Sci U S A. 1995 Apr 25;92(9):3874-8. PMID:7731999
