Structural probing of Zn(II), Cd(II) and Hg(II) binding to human ubiquitin.
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 orthorhombic to cubic form; Glu16 and Glu18, 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.
Falini
Giuseppe
G
Dipartimento di Chimica, G. Ciamician, Università di Bologna, via Selmi 2, 40126, Bologna, Italy. giuseppe.falini@unibo.it
Fermani
Simona
S
Tosi
Giovanna
G
Arnesano
Fabio
F
Natile
Giovanni
G
D002104:Cadmium / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008628:Mercury / Q000737:chemistry* / Q000378:metabolism; D008968:Molecular Conformation; D017434:Protein Structure, Tertiary; D025801:Ubiquitin / Q000737:chemistry* / Q000378:metabolism; D015032:Zinc / Q000737:chemistry* / Q000378:metabolism
D025801:Ubiquitin; D002104:Cadmium; D008628:Mercury; D015032:Zinc