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Iron: Non-Heme Proteins with Diiron-Carboxylate Active Sites

  1. Donald M. Kurtz Jr,
  2. Emily Boice,
  3. Jonathan D. Caranto,
  4. Rosanne E. Frederick,
  5. Cesar A. Masitas,
  6. Kyle D. Miner

Published Online: 23 SEP 2013

DOI: 10.1002/9781119951438.eibc0105.pub2

Encyclopedia of Inorganic and Bioinorganic Chemistry

Encyclopedia of Inorganic and Bioinorganic Chemistry

How to Cite

Kurtz, D. M., Boice, E., Caranto, J. D., Frederick, R. E., Masitas, C. A. and Miner, K. D. 2013. Iron: Non-Heme Proteins with Diiron-Carboxylate Active Sites. Encyclopedia of Inorganic and Bioinorganic Chemistry. 1–18.

Author Information

  1. University of Texas at San Antonio, San Antonio, TX, USA

  1. Update based on the original article by Donald M. Kurtz, Jr, Encyclopedia of Inorganic Chemistry © 2005 John Wiley & Sons, Ltd

Publication History

  1. Published Online: 23 SEP 2013

Abstract

Non-heme diiron-carboxylate (NHDC) active sites are found in several classes of monooxygenases, oxidases, and dioxygen transport or sensing proteins, as well as a few metallohydrolases. The unique and defining structural feature of NHDC sites consists of two non-heme irons bridged by at least one carboxylate-containing amino acid residue. A second characteristic feature is a bridging solvent ligand, either oxo or hydroxo in at least the diferric state. NHDC sites also feature terminal ligands derived from histidine and carboxylate residues. The hemerythrin superfamily functions have expanded from reversible dioxygen binding to include sensing of iron, dioxygen, or redox status. Substantial progress has been made in characterization of flavo-diiron enzymes, including its nitric oxide reductase mechanism. A diiron urease is a recent addition to the metallohydrolase family. The variety of characterized NHDC O2-activating enzymes has increased substantially since the previous compilation in this encyclopedia. Novel monooxygenation mechanisms have been identified.

Keywords:

  • diiron;
  • binuclear;
  • non-heme;
  • oxidase;
  • monooxygenase;
  • hydroxylase;
  • carboxylate bridge;
  • oxo bridge;
  • histidine ligand;
  • metallohydrolase;
  • phosphatase;
  • ferritin;
  • hemerythrin