Structural Probing Of Zn(Ⅱ), Cd(Ⅱ) And Hg(Ⅱ) Binding To Human Ubiquitin

摘要

A structural investigation performed on adducts of human ubiquitin with group-12 metal ions reveals common preferential anchoring sites, the most populated one being His68; at higher metal ion concentration a second and a third site, close to the N-terminus of the protein, become populated and promote a polymorphic transition from orthorhomhic to cubic form; Glu l6 and Glul8, involved in the latter metal binding, undergo a remarkable displacement from their position in native ubiquitin; the aggregate stereochemistry appears to be driven by the clustering of deshielded backbone hydrogen-bond patches, and metal ions foster this process.