This family includes the EfeO domain, an essential component of the EfeUOB operon which is highly conserved in bacteria. However, its biochemical function is unknown. EfeO contains an N-terminal cupredoxin (CUP)-like domain and C-terminal imelysin-like domain that may bind iron. Algp7, a member of EfeO family protein from Sphingomonas sp. A1, is found to bind alginate at neutral pH, but does not contain the CUP domain, thus having a role that does not seem to be related to iron uptake. Some members of this family are fused to an N-terminal putative EfeU ion permease domain. The imelysin-like domain of this family also contains the GxHxxE sequence motif and a highly conserved functional site, suggesting a similar role to other imelysin family proteins containing the same motif.
Jiyao W et al.(2023). "The conserved domain database in 2023.",