A novel protein-mineral interface.
Alexeev, D., Zhu, H., Guo, M., Zhong, W., Hunter, D.J., Yang, W., Campopiano, D.J., Sadler, P.J.(2003) Nat Struct Biol 10: 297-302
- PubMed: 12598891 
- DOI: https://doi.org/10.1038/nsb903
- Primary Citation of Related Structures:  
1O7T - PubMed Abstract: 
Transferrins transport Fe3+ and other metal ions in mononuclear-binding sites. We present the first evidence that a member of the transferrin superfamily is able to recognize multi-nuclear oxo-metal clusters, small mineral fragments that are the most abundant forms of many metals in the environment. We show that the ferric ion-binding protein from Neisseria gonorrhoeae (nFbp) readily binds clusters of Fe3+, Ti4+, Zr4+ or Hf4+ in solution. The 1.7 A resolution crystal structure of Hf-nFbp reveals three distinct types of clusters in an open, positively charged cleft between two hinged protein domains. A di-tyrosyl cluster nucleation motif (Tyr195-Tyr196) is situated at the bottom of this cleft and binds either a trinuclear oxo-Hf cluster, which is capped by phosphate, or a pentanuclear cluster, which in turn can be capped with phosphate. This first high-resolution structure of a protein-mineral interface suggests a novel metal-uptake mechanism and provides a model for protein-mediated mineralization/dissimilation, which plays a critical role in geochemical processes.
Organizational Affiliation: 
Institute of Cell and Molecular Biology, Michael Swann Building, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK.