This family is comprised of bacterial relatives of the mammalian members of the BAX inhibitor (BI)-1 like family of small transmembrane proteins, which have been shown to have an antiapoptotic effect either by stimulating the antiapoptotic function of Bcl-2, a well-characterized oncogene, or by inhibiting the proapoptotic effect of Bax, another member of the Bcl-2 family. In plants, BI-1 like proteins play a role in pathogen resistance. A characterized prokaryotic member, Escherichia coli YccA, has been shown to interact with ATP-dependent protease FtsH, which degrades abnormal membrane proteins as part of a quality control mechanism to keep the integrity of biological membranes.
Jiyao W et al.(2023). "The conserved domain database in 2023.",