YqfD is part of the sigma-E regulon in the sporulation program of endospore-forming Gram-positive bacteria. Mutation results in a sporulation defect in Bacillus subtilis. Members are found in all currently known endospore-forming bacteria, including the genera Bacillus, Symbiobacterium, Carboxydothermus, Clostridium, and Thermoanaerobacter. [Cellular processes, Sporulation and germination]
Jiyao W et al.(2023). "The conserved domain database in 2023.",