This represents the stage III sporulation protein AE, which is encoded in a spore formation operon spoIIIAABCDEFGH under the control of sigma G. A comparative genome analysis of all sequenced genomes of Firmicutes shows that the proteins are strictly conserved among the sub-set of endospore-forming species.
Jiyao W et al.(2023). "The conserved domain database in 2023.",