Abstract 2708 Functional diversification and convergence across the heme-binding split-barrel and DRI families

Heme has a critical role in the chemical framework of the cell as an essential protein cofactor and signaling molecule that controls diverse processes and molecular interactions. Combining bioinformatic approaches with targeted experimentation, we've uncovered a large multi-functional family of putative enzymatic and non-enzymatic proteins involved in heme metabolism and sensing across bacteria, plants, and algae. One subfamily (homolog of HugZ (HOZ)) is embedded in the “FMN-binding split barrel” superfamily, where amino acid mutation combined with independent instances of domain fusion in prokaryotes, plants, and algae have resulted in separate groups of proteins that can bind heme and either catalyze its degradation or function as non-enzymatic heme sensors.