Implicated in the coupling of mother cell to forespore gene expression. Required for spore formation at 37 degrees Celsius, but not at 30 degrees Celsius. SpoIVFA plays a central role in both maintaining the SpoIVFA/BofA/SpoIVFB complex and anchoring it to the outer forespore membrane. SpoIVFA brings BofA into close proximity to SpoIVFB, allowing BofA to inhibit SpoIVFB. Increased accumulation of SpoIVFA seems to inhibit the activity of SpoIVFB and thus regulates the activation of sigma-K. Forms a complex with BofA and SpoIVFB localized in the mother-cell membrane surrounding the forespore. Transcribed during the stage II, but not required until stage IV of sporulation. May be degraded by FtsH. It is stabilized by an ftsH disruption mutant, and in a probably independent fashion, by overexpression of BofA.