This family contains the bacterial stage II sporulation protein P (SpoIIP) (approximately 350 residues long). It has been shown that a block in polar cytokinesis in Bacillus subtilis is mediated partly by transcription of spoIID, spoIIM and spoIIP. This inhibition of polar division is involved in the locking in of asymmetry after the formation of a polar septum during sporulation [1]. Engulfment in Bacillus subtilis is mediated by two complementary systems: the first includes the proteins SpoIID, SpoIIM and SpoIIP (DMP) which carry out the engulfment, and the second includes the SpoIIQ-SpoIIIAGH (Q-AH) zipper, that recruits other proteins to the septum in a second-phase of the engulfment. The course of events follows as the incorporation firstly of SpoIIB into the septum during division to serve directly or indirectly as a landmark for localising SpoIIM and then SpoIIP and SpoIID to the septum. SpoIIP and SpoIID interact together to form part of the DMP complex [3]. SpoIIP itself has been identified as an autolysin with peptidoglycan hydrolase activity [2].

1: A vital stain for studying membrane dynamics in bacteria: a novel mechanism controlling septation during Bacillus subtilis sporulation. Pogliano J, Osborne N, Sharp MD, Abanes-De Mello A, Perez A, Sun YL, Pogliano K; Mol Microbiol. 1999;31:1149-1159. PMID:10096082

2: Engulfment during sporulation in Bacillus subtilis is governed by a multi-protein complex containing tandemly acting autolysins. Chastanet A, Losick R; Mol Microbiol. 2007;64:139-152. PMID:17376078

3: Dual localization pathways for the engulfment proteins during Bacillus subtilis sporulation. Aung S, Shum J, Abanes-De Mello A, Broder DH, Fredlund-Gutierrez J, Chiba S, Pogliano K; Mol Microbiol. 2007;65:1534-1546. PMID:17824930