The insect pathogenic Gram-positive Bacillus thuringiensis secretes immune inhibitor A, a metallopeptidase, which specifically cleaves host antibacterial proteins. A homologue of immune inhibitor A, PrtV, has been identified in the Gram-negative human pathogen Vibrio cholerae [4]. The structure revealed four domains: a pro-peptide, a catalytic domain (represented in this entry), a domain reminiscent of viral envelope glycoproteins (VEG) and a MAM domain grafted into the latter [6].

1: Identification of genes involved in the activation of the Bacillus thuringiensis inhA metalloprotease gene at the onset of sporulation. Grandvalet C, Gominet M, Lereclus D; Microbiology 2001;147:1805-1813. PMID:11429458

2: Characterization of the exosporium of Bacillus cereus. Charlton S, Moir AJ, Baillie L, Moir A; J Appl Microbiol 1999;87:241-245. PMID:10475957

3: Molecular characterization of immune inhibitor A, a secreted virulence protease from Bacillus thuringiensis. Lovgren A, Zhang M, Engstrom A, Dalhammar G, Landen R; Mol Microbiol 1990;4:2137-2146. PMID:2089225

4: Characterization of the Vibrio cholerae El Tor lipase operon lipAB and a protease gene downstream of the hly region. Ogierman MA, Fallarino A, Riess T, Williams SG, Attridge SR, Manning PA; J Bacteriol 1997;179:7072-7080. PMID:9371455

5: The InhA2 metalloprotease of Bacillus thuringiensis strain 407 is required for pathogenicity in insects infected via the oral route. Fedhila S, Nel P, Lereclus D; J Bacteriol 2002;184:3296-3304. PMID:12029046

6: Structural Basis for Latency and Function of Immune Inhibitor A Metallopeptidase, a Modulator of the Bacillus anthracis Secretome. Arolas JL, Goulas T, Pomerantsev AP, Leppla SH, Gomis-Ruth FX; Structure. 2016;24:25-36. PMID:26745529