The ODP (Oxygen-binding Di-iron Protein) domain is a distinct member of the metallo-beta-lactamase superfamily recruited to various bacterial and archaeal signal transduction pathways, including chemotaxis, to function as oxygen and iron sensors (1). ODP was shown to act as a sensor for chemotactic responses to both iron and oxygen in the human pathogen Treponema denticola (Td). The ODP di-iron site binds oxygen at high affinity to reversibly form an unusually stable peroxo adduct.

1: A di-iron protein recruited as an Fe[II] and oxygen sensor for bacterial chemotaxis functions by stabilizing an iron-peroxy species. Muok AR, Deng Y, Gumerov VM, Chong JE, DeRosa JR, Kurniyati K, Coleman RE, Lancaster KM, Li C, Zhulin IB, Crane BR; Proc Natl Acad Sci U S A. 2019;116:14955-14960. PMID:31270241