Repair of Iron Center Proteins—A Different Class of Hemerythrin-like Proteins

Abstract

Repair of Iron Center proteins (RIC) form a family of di-iron proteins that are widely spread in the microbial world. RICs contain a binuclear nonheme iron site in a four-helix bundle fold, two basic features of hemerythrin-like proteins. In this work, we review the data on microbial RICs including how their genes are regulated and contribute to the survival of pathogenic bacteria. We gathered the currently available biochemical, spectroscopic and structural data on RICs with a particular focus on Escherichia coli RIC (also known as YtfE), which remains the best-studied protein with extensive biochemical characterization. Additionally, we present novel structural data for Escherichia coli YtfE harboring a di-manganese site and the protein’s affinity for this metal. The networking of protein interactions involving YtfE is also described and integrated into the proposed physiological role as an iron donor for reassembling of stress-damaged iron-sulfur centers.

The Oxidative Stress-Induced Hypothetical Protein PG_0686 in Porphyromonas gingivalis W83 Is a Novel Diguanylate Cyclase

“…Similarly, iron, or other metals (such as cadmium), can be bound for storage, detoxification, or function in some other mechanism unrelated to the binding of metals or oxygen ( 49 ). In addition, it has been reported that hemerythrins may play a role in intracellular iron homestatsis, and the repair of iron centers in certain bacteria ( 65 , 66 ). PG_0686 lacks the classic 5 His motif featured in other hemerythrins, and has only one histidine residue predicted to be involved in chloro diiron-oxo binding; as such, it appears to be a part of the group of non-canonical hemerythrin sequences.…”