Metal-mediated self-assembly of a beta-sandwich protein.
The beta-sandwich cupredoxin Plastocyanin (Pc) was found to self-assemble in the presence of Zn(2+), a known mediator of protein-protein interfaces. Diffraction-quality crystals of Pc grew from solutions containing zinc acetate as the sole precipitant. Di- and trinuclear zinc sites contribute to the crystal contacts in this structure. A different crystal form, also involving numerous zinc bridging ions, was obtained in the presence of poly(ethylene glycol) 8 000. Comparison of the two crystal forms reveals the effect of macromolecular crowding on self-assembly. Solution-state structural characterisation of the Zn(2+)-mediated Pc oligomers was performed by using a combination of chemical shift perturbation mapping and small-angle X-ray scattering. The data indicate the formation of dimers in solution. The implications for metal-mediated assembly and crystallisation are discussed.
Crowley
Peter B
PB
UCD Centre for Synthesis and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland. peter.crowley@nuigalway.ie
Matias
Pedro M
PM
Khan
Amir R
AR
Roessle
Manfred
M
Svergun
Dmitri I
DI
D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D018360:Crystallography, X-Ray; D000458:Cyanobacteria; D008958:Models, Molecular; D010084:Oxidation-Reduction; D010970:Plastocyanin / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D055503:Protein Multimerization / Q000187:drug effects; D020836:Protein Structure, Quaternary / Q000187:drug effects; D053838:Scattering, Small Angle; D012996:Solutions; D015032:Zinc / Q000494:pharmacology*
D001426:Bacterial Proteins; D012996:Solutions; D010970:Plastocyanin; D015032:Zinc