Open AccessInteraction of an echinomycin–DNA complex with manganese ions
Author(s) -
Pfoh Roland,
CuestaSeijo Jose A.,
Sheldrick George M.
Publication year - 2009
Publication title -
acta crystallographica section f
Language(s) - English
Resource type - Journals
ISSN - 1744-3091
DOI - 10.1107/s1744309109019654
Subject(s) - manganese , duplex (building) , crystallography , intercalation (chemistry) , pairing , base pair , chemistry , guanine , dna , stereochemistry , nucleotide , physics , inorganic chemistry , condensed matter physics , biochemistry , organic chemistry , gene , superconductivity
The crystal structure of an echinomycin–d(ACGTACGT) duplex interacting with manganese(II) was solved by Mn‐SAD using in‐house data and refined to 1.1 Å resolution against synchrotron data. This complex crystallizes in a different space group compared with related complexes and shows a different mode of base pairing next to the bis‐intercalation site, suggesting that the energy difference between Hoogsteen and Watson–Crick pairing is rather small. The binding of manganese to N7 of guanine is only possible because of DNA unwinding induced by the echinomycin, which might help to explain the mode of action of the drug.