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Circular dichroism spectroscopy reveals invariant conformation of guanine runs in DNA
Author(s) -
Kypr Jaroslav,
Vorlíčková Michaela
Publication year - 2002
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.10112
Subject(s) - antiparallel (mathematics) , guanine , chemistry , circular dichroism , duplex (building) , dna , crystallography , stacking , spectroscopy , stereochemistry , biophysics , nucleotide , biochemistry , physics , biology , organic chemistry , quantum mechanics , magnetic field , gene
We demonstrate that the characteristic circular dichroism (CD) features of the parallel‐stranded DNA tetraplex of d(G 4 ), especially the strong band at 260 nm, are characteristic for the B and A forms of the antiparallel duplex of d(C 4 G 4 ). Hence, this band evidently originates from intrastrand guanine–guanine stacking, which is therefore very similar in the duplex and tetraplex DNA. In addition, the same type of the CD spectrum is provided by the ordered single strand of d(GA) 10 . This observation suggests that the ordered single strand of d(GA) 10 is stabilized by a core of guanines stacked like in the parallel tetraplex. This view is used to start the modeling of the molecular structure of the ordered d(GA) 10 single strand. Our studies suggest that guanine itself is strong enough to stabilize various secondary structures of DNA, which is a property relevant to thinking about the origin and evolution of molecular replicators. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 275–277, 2002