Globin domain of uncharacterized oxidoreductases containing a FAD/NADH binding domain
This subfamily is composed of uncharacterized proteins containing an N-terminal myoglobin-like (M family globin) domain and a C-terminal oxygenase reductase FAD/NADH binding domain belonging to the ferredoxin reductase (FNR) family and is usually part of multi-component bacterial oxygenases which oxidize hydrocarbons using oxygen as the oxidant. The domain architecture of this subfamily is similar to flavohemoglobins, which function primarily as nitric oxide dioxygenases (NODs, EC 1.14.12.17), converting NO and O2 to inert NO3- (nitrate). They protect from nitrosative stress (the broad range of cellular toxicities caused by NO), and modulate NO signaling pathways. NO scavenging by flavoHb attenuates the expression of the nitrosative stress response, affects the swarming behavior of Escherichia coli, and maintains squid-Vibrio fischeri and Medicago truncatula-Sinorhizobium meliloti symbioses.
Jiyao W et al.(2023). "The conserved domain database in 2023.",