2dbe
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CRYSTAL STRUCTURE OF A BERENIL-DODECANUCLEOTIDE COMPLEX: THE ROLE OF WATER IN SEQUENCE-SPECIFIC LIGAND BINDING
OverviewOverview
The three-dimensional structure of a complex between the dodecanucleotide, d(CGCGAATTCGCG) and the anti-trypanocidal drug berenil, has been, determined to a resolution of 2.5 A. The structure has been solved by, molecular replacement and refined to an R factor of 0.177. A total of 49, water molecules have been located. The drug is bound at the 5'-AAT-3', region of the oligonucleotide. At one end of the drug the amidinium group, is in hydrogen-bonded contact with N3 of the adenine base complementary to, the thymine of the AAT. The other amidinium group does not make direct, interactions with the DNA. Instead, a water molecule mediates between, them. This is in hydrogen-bonded contact with an amidinium nitrogen atom, N3 of the 5' end adenine base and the ring oxygen atom of an adjacent, deoxyribose. Molecular mechanics calculations have been performed on this, complex, with the drug at various positions along the sequence. These show, that the observed position is only 0.8 kcal/mol higher in energy than the, best position. It is suggested that there is a broad energy well in the, AATT region for this drug, and that water molecules as well as the, neighbouring sequence, will determine precise positioning. More general, aspects of minor groove binding are discussed.
About this StructureAbout this Structure
2DBE is a Protein complex structure of sequences from [1] with BRN as ligand. Full crystallographic information is available from OCA.
ReferenceReference
Crystal structure of a berenil-dodecanucleotide complex: the role of water in sequence-specific ligand binding., Brown DG, Sanderson MR, Skelly JV, Jenkins TC, Brown T, Garman E, Stuart DI, Neidle S, EMBO J. 1990 Apr;9(4):1329-34. PMID:2323343
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