The selective B-A conformational transition of the central dinucleotide (CpG) segment of d(CAATCCGGATTG)2 induced by delta-Co(en)3(3+)

Biochem Mol Biol Int. 1996 Feb;38(2):383-91.

Abstract

The binding of Co(NH3)6(3+), delta-Co(en)3(3+) and delta-Rh(en)3(3+) to the dodecanucleotide d(CAATCCGGATTG)2 has been studied by 1H NMR. Addition of Co(NH3)6(3+), delta-Co(en)3(3+) or delta-Rh(en)3(3+) to d(CAATCCGGATTG)2 induce a similar pattern of chemical shift movements of the dodecanucleotide base protons. Analysis of the chemical shift changes as a function of added metal-ion complex shows that the binding affinity for d(CAATCCGGATTG)2 decreases in the order: delta-Co(en)3(3+) > delta-Rh(en)3(3+) > Co(NH3)6(3+). Addition of a saturating ratio of delta-Co(en)3(3+) to d(CAATCCGGATTG)2 induces a selective B to A type-DNA transition for the central CpG segment of the dodecanucleotide, with all other nucleotide residues maintaining the B-type conformation.

MeSH terms

  • Base Sequence
  • Cobalt / chemistry*
  • DNA / chemistry*
  • Dinucleoside Phosphates / chemistry
  • Ethylenediamines / chemistry*
  • Magnetic Resonance Spectroscopy
  • Molecular Sequence Data
  • Nucleic Acid Conformation*
  • Oligodeoxyribonucleotides / chemistry
  • Organometallic Compounds / chemistry*
  • Stereoisomerism

Substances

  • Dinucleoside Phosphates
  • Ethylenediamines
  • Oligodeoxyribonucleotides
  • Organometallic Compounds
  • tris(ethylenediamine)cobalt(III)
  • cytidylyl-3'-5'-guanosine
  • Cobalt
  • DNA