Plays a central role in the sigma-K checkpoint which coordinates gene expression during the later stages of spore formation. The protease is activated by trans cleavage of the zymogen precursor producing SpoIVB-45 kDa. This undergoes further trimming by cis cleavage to form SpoIVB-43 kDa and SpoIVB-42 kDa. The protease then cleaves the C-terminus of the SpoIVFA metalloprotease activating the latter. Self-cleaves 52-Val-|-Asn-53, 62-Ala-|-Phe-63 and 74-Val-|-Thr-75 at the N-terminus of SpoIVB. The zymogen is inhibited from undergoing autoactivation by BofC. The protease is inactivated by proteolytic cleavage. The PDZ domain mediates interaction with another SpoIVB protein during transactivation. Also mediates interaction with BofA during cleavage of SpoIVFA. Transcribed in low amounts by sigma-F. Transcribed during stage III of sporogenesis by sigma-G.