A zipper-like duplex in DNA: the crystal structure of d(GCGAAAGCT) at 2.1 A resolution.
Shepard, W., Cruse, W.B., Fourme, R., de la Fortelle, E., Prange, T.(1998) Structure 6: 849-861
- PubMed: 9687367 
- DOI: https://doi.org/10.1016/s0969-2126(98)00087-2
- Primary Citation of Related Structures:  
376D - PubMed Abstract: 
The replication origin of the single-stranded (ss)DNA bacteriophage G4 has been proposed to fold into a hairpin loop containing the sequence GCGAAAGC. This sequence comprises a purine-rich motif (GAAA), which also occurs in conserved repetitive sequences of centromeric DNA. ssDNA analogues of these sequences often show exceptional stability which is associated with hairpin loops or unusual duplexes, and may be important in DNA replication and centromere function. Nuclear magnetic resonance (NMR) studies indicate that the GCGAAAGC sequence forms a hairpin loop in solution, while centromere-like repeats dimerise into unusual duplexes. The factors stabilising these unusual secondary structure elements in ssDNA, however, are poorly understood.
Organizational Affiliation: 
LURE, Université Paris-Sud, Orsay, France. shepard@lure.u-psud.fr