1bzo

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spinqualitylabelsall models 1bzo, resolution 2.1Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

THREE-DIMENSIONAL STRUCTURE OF PROKARYOTIC CU,ZN SUPEROXIDE DISMUTASE FROM P.LEIOGNATHI, SOLVED BY X-RAY CRYSTALLOGRAPHY.

Overview

Prokaryotic Cu,Zn superoxide dismutases are characterized by a distinct, quaternary structure, as compared to that of the homologous eukaryotic, enzymes. Here we report a newly determined crystal structure of the, dimeric Cu,Zn superoxide dismutase from Photobacterium leiognathi, (crystallized in space group R32, refined at 2.5 A resolution, R-factor, 0.19) and analyse it in comparison with that of the monomeric enzyme from, Escherichia coli. The dimeric assembly, observed also in a previously, studied monoclinic crystal form of P. leiognathi Cu,Zn superoxide, dismutase, is based on a ring-shaped subunit contact region, defining a, solvated interface cavity. Three clusters of neighbouring residues play a, direct role in the stabilization of the quaternary assembly. The present, analysis, extended to the amino acid sequences of the other 11 known, prokaryotic Cu,Zn superoxide dismutases, shows that at least in five other, prokaryotic enzymes the interface residue clusters are under strong, evolutionary constraint, suggesting the attainment of a quaternary, structure coincident with that of P. leiognathi Cu,Zn superoxide, dismutase. Calculation of electrostatic fields for both the enzymes from, E. coli and P. leiognathi shows that the monomeric/dimeric association, behaviour displayed by prokaryotic Cu, Zn superoxide dismutases is related, to the distribution of surface charged residues. Moreover, Brownian, dynamics simulations reproduce closely the observed enzyme:substrate, association rates, highlighting the role of the active site neighbouring, residues in determining the dismutase catalytic properties.

About this Structure

1BZO is a Single protein structure of sequence from Photobacterium leiognathi with ZN, CU and IUM as ligands. Active as Superoxide dismutase, with EC number 1.15.1.1 Full crystallographic information is available from OCA.

Reference

Evolutionary constraints for dimer formation in prokaryotic Cu,Zn superoxide dismutase., Bordo D, Matak D, Djinovic-Carugo K, Rosano C, Pesce A, Bolognesi M, Stroppolo ME, Falconi M, Battistoni A, Desideri A, J Mol Biol. 1999 Jan 8;285(1):283-96. PMID:9878406

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