Component of antiplasmid transformation system Wadjet type I, composed of JetA, JetB, JetC and JetD. Expression of Wadjet type I in B.subtilis (strain BEST7003) reduces the transformation efficiency of plasmid pHCMC05 (PubMed:29371424). May be an ATPase (Probable). When this gene is missing the Wadjet system does not confer plasmid-transformation resistance in B.subtilis. Extended N-terminus.