Structural characterization and biological implications of di-zinc binding in the ferroxidase center of Streptococcus pyogenes Dpr

详细信息    查看全文

• 作者：Teemu Haikarainen ; Chih-Cheng Tsou ; Jiunn-Jong Wu ; Anastassios C. Papageorgiou
• 关键词：Ferroxidase ; Ferritins ; Zinc ; Oxidative stress ; Streptococcal proteins ; Fenton reaction ; Hydrogen peroxide
• 刊名：Biochemical and Biophysical Research Communications
• 出版年：2010
• 出版时间：30 July 2010
• 年：2010
• 卷：398
• 期：3
• 页码：361-365
• 全文大小：797 K

文摘

Dps proteins contain a ferroxidase site that binds and oxidizes iron, thereby preventing hydroxyl radical formation by Fenton reaction. Although the involvement of a di-iron ferroxidase site has been suggested, X-ray crystal structures of various Dps members have shown either one or two iron cations with various occupancies despite the high structural conservation of the site. Similarly, structural studies with zinc, a redox-stable replacement for iron, have shown the binding of either one or two zinc ions. Here, the crystal structure of Streptococcus pyogenes Dpr in complex with zinc reveals the binding of two zinc cations in the ferroxidase center and an additional zinc-binding site at the surface of the protein. The results suggest a structural basis for the protection of Streptococcus pyogenes in zinc stress conditions and provide a clear evidence for a di-zinc and di-iron ferroxidase site in Streptococcus pyogenes Dpr protein.