Structural highlights
Publication Abstract from PubMedMany bacteria contain cytoplasmic chemoreceptors that lack sensor domains. Here, we demonstrate that such cytoplasmic receptors found in 8 different bacterial and archaeal phyla genetically couple to metalloproteins related to beta-lactamases and nitric oxide reductases. We show that this oxygen-binding di-iron protein (ODP) acts 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 mu-peroxo adduct. Crystal structures of ODP from Td and the thermophile Thermotoga maritima (Tm) in the Fe[III]2-O2 (2-), Zn[II], and apo states display differences in subunit association, conformation, and metal coordination that indicate potential mechanisms for sensing. In reconstituted systems, iron-peroxo ODP destabilizes the phosphorylated form of the receptor-coupled histidine kinase CheA, thereby providing a biochemical link between oxygen sensing and chemotaxis in diverse prokaryotes, including anaerobes of ancient origin. 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 Jul 3. pii: 1904234116. doi:, 10.1073/pnas.1904234116. PMID:31270241[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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