2CF7

Asp74Ala mutant crystal structure for Dps-like peroxide resistance protein Dpr from Streptococcus suis.

Summary for 2CF7

• Entry DOI: 10.2210/pdb2cf7/pdb
• Related: 1UMN 2BW1
• Descriptor: DPR, 4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID, CALCIUM ION, ... (5 entities in total)
• Functional Keywords: peroxide resistance, dps-family, ferritin-like, ferroxidase, iron-binding
• Biological source: STREPTOCOCCUS SUIS
• Total number of polymer chains: 12
• Total formula weight: 223455.50

Authors

Kauko, A.,Pulliainen, A.T.,Haataja, S.,Finne, J.,Papageorgiou, A.C. (deposition date: 2006-02-16, release date: 2006-09-28, Last modification date: 2023-12-13)

Primary citation

Kauko, A.,Pulliainen, A.T.,Haataja, S.,Meyer-Klaucke, W.,Finne, J.,Papageorgiou, A.C.
Iron incorporation in Streptococcus suis Dps-like peroxide resistance protein Dpr requires mobility in the ferroxidase center and leads to the formation of a ferrihydrite-like core.
J. Mol. Biol., 364:97-109, 2006

PubMed Abstract: The Dps-like peroxide resistance protein (Dpr) is a dodecameric protein that protects the human and swine pathogen Streptococcus suis from hydrogen peroxide by removing free Fe2+ from the cytosol. Subsequent oxidation of iron by Dpr results in the deposition of Fe3+ inside the protein's central cavity. Structural changes that occur in the ferroxidase center were studied by X-ray crystallography after soaking Dpr crystals with Fe2+ in the presence of sodium dithionite. Twelve iron-binding sites were identified with each site formed by residues Asp74 and Glu78 from one subunit, and Asp63, His47 and His59 from a 2-fold symmetry-related subunit. Compared to the iron-free Dpr, Asp74 and Glu78 were found to be the most flexible amino acid residues and able to adopt a variety of conformations in different subunits. The crystal structure of an Asp74Ala Dpr mutant soaked with a Fe2+ -solution revealed variations in the Asp63 position and no iron bound to the ferroxidase center. These results indicate an intrinsic flexibility in the active site that may be important for the catalytic reaction and subsequent nucleation events. Two iron cores with remarkably different features were identified in Dpr using X-ray absorption spectroscopy. Purified Dpr was found to have a small-size iron core with only approximately 16 iron atoms/dodecamer forming a ferritin-like ferrihydrite structure. Because of its size, this core represents the smallest iron core identified so far in ferritins and other Dps-like proteins. A large-size core (approximately 180 iron atoms/dodecamer) formed after incubating the protein with a ferrous solution shows differences in iron coordination compared to the small size core. Characterization of the two iron cores in Dpr could provide insights into nucleation events and the mechanism of iron core growth in the Dps family of proteins.

PubMed: 16997323
DOI: 10.1016/j.jmb.2006.08.061

Experimental method

X-RAY DIFFRACTION (1.5 Å)