Component of antiviral defense system DISARM (defense island system associated with restriction-modification), composed of DrmE, DrmA, DrmB, DrmC and DrmMII. DISARM is probably a multi-gene restriction module, this subunit has an unknown function. Expression of DISARM in B.subtilis (strain BEST7003) confers resistance to phages Nf, phi29, phi105, phi3T, SPO1, SPR and SPP1. Protection is over 10(7)-fold against phi3T, 10(4)-10(5)-fold against Nf, phi29, phi105 and SPR, 100-fold against SPO1 and 10-fold against SPP1. DISARM does not interfere with phage adsorption, but instead interferes with (phi3T) DNA replication early in its cycle, preventing replication, circularization and lysogeny and probably causes phage DNA degradation (DNA is degraded in SPP1-infected cells). When this gene is missing the DISARM system does not confer Nf, phi3T or SPO1 resistance in B.subtilis.