Guanine Can Direct Binding Specificity of Ru-dipyridophenazine (dppz) Complexes to DNA through Steric Effects.

ABSTRACT: X-ray crystal structures of three Λ-[Ru(L)₂ dppz]²⁺ complexes (dppz=dipyridophenazine; L=1,10-phenanthroline (phen), 2,2'-bipyridine (bpy)) bound to d((5BrC)GGC/GCCG) showed the compounds intercalated at a 5'-CG-3' step. The compounds bind through canted intercalation, with the binding angle determined by the guanine NH₂ group, in contrast to symmetrical intercalation previously observed at 5'-TA-3' sites. This result suggests that canted intercalation is preferred at 5'-CG-3' sites even though the site itself is symmetrical, and we hypothesise that symmetrical intercalation in a 5'-CG-3' step could give rise to a longer luminescence lifetime than canted intercalation.

SUBMITTER: Hall JP 

PROVIDER: S-EPMC5412927 | biostudies-literature |

REPOSITORIES: biostudies-literature