Metal Ion Binding at the Catalytic Site Induces Widely Distributed Changes in a Sequence Specific Protein-DNA Complex.

ABSTRACT: Metal ion cofactors can alter the energetics and specificity of sequence specific protein-DNA interactions, but it is unknown if the underlying effects on structure and dynamics are local or dispersed throughout the protein-DNA complex. This work uses EcoRV endonuclease as a model, and catalytically inactive lanthanide ions, which replace the Mg²⁺ cofactor. Nuclear magnetic resonance (NMR) titrations indicate that four Lu³⁺ or two La³⁺ cations bind, and two new crystal structures confirm that Lu³⁺ binding is confined to the active sites. NMR spectra show that the metal-free EcoRV complex with cognate (GATATC) DNA is structurally distinct from the nonspecific complex, and that metal ion binding sites are not assembled in the nonspecific complex. N

SUBMITTER: Sinha K 

PROVIDER: S-EPMC5402698 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature