2XJN

Crystal structure of Streptococcus suis Dpr with copper

Summary for 2XJN

• Entry DOI: 10.2210/pdb2xjn/pdb
• Related: 1UMN 2BW1 2CF7 2UX1 2V15 2XJM 2XJO 2XKQ
• Descriptor: DNA PROTECTION DURING STARVATION PROTEIN, COPPER (II) ION, CHLORIDE ION, ... (6 entities in total)
• Functional Keywords: oxidoreductase, iron storage, metal-binding
• Biological source: STREPTOCOCCUS SUIS
• Total number of polymer chains: 12
• Total formula weight: 225785.60

Authors

Haikarainen, T.,Thanassoulas, A.,Stavros, P.,Nounesis, G.,Haataja, S.,Papageorgiou, A.C. (deposition date: 2010-07-06, release date: 2010-11-24, Last modification date: 2024-05-08)

Primary citation

Haikarainen, T.,Thanassoulas, A.,Stavros, P.,Nounesis, G.,Haataja, S.,Papageorgiou, A.C.
Structural and Thermodynamic Characterization of Metal Ion Binding in Streptococcus Suis Dpr.
J.Mol.Biol., 405:448-, 2011

PubMed Abstract: The use of protein cages for the creation of novel inorganic nanomaterials has attracted considerable attention in recent years. Ferritins are among the most commonly used protein cages in nanoscience. Accordingly, the binding of various metals to ferritins has been studied extensively. Dps (DNA-binding protein from starved cells)-like proteins belong to the ferritin superfamily. In contrast to ferritins, Dps-like proteins form 12-mers instead of 24-mers, have a different ferroxidase center, and are able to store a smaller amount of iron atoms in a hollow cavity (up to ∼500, instead of the ∼4500 iron atoms found in ferritins). With the exception of iron, the binding of other metal cations to Dps proteins has not been studied in detail. Here, the binding of six divalent metal ions (Zn(2+), Mn(2+), Ni(2+), Co(2+), Cu(2+), and Mg(2+)) to Streptococcus suisDps-like peroxide resistance protein (SsDpr) was characterized by X-ray crystallography and isothermal titration calorimetry (ITC). All metal cations, except for Mg(2+), were found to bind to the ferroxidase center similarly to Fe(2+), with moderate affinity (binding constants between 0.1×10(5) M(-1) and 5×10(5) M(-1)). The stoichiometry of binding, as deduced by ITC data, suggested the presence of a dication ferroxidase site. No other metal binding sites were identified in the protein. The results presented here demonstrate the ability of SsDpr to bind various metals as substitutes for iron and will help in better understanding protein-metal interactions in the Dps family of proteins as potential metal nanocontainers.

PubMed: 21056572
DOI: 10.1016/J.JMB.2010.10.058

Experimental method

X-RAY DIFFRACTION (2.1 Å)