title: Bacillus subtilis-phage phi 1 overcomes host-controlled restriction by producing BamNx inhibitor protein.
abstract: Bacillus amyloliquefaciens N produces two restriction enzymes, BamNI and BamNx. Subtilis-phage phi 1 is strongly restricted by BamNx. We isolated phi 1 rH, a mutant of phage phi 1, which overcame the BamNx-restriction by producing inhibitor. This inhibitor inactivated BamNx specifically and reversibly. The inhibitor directly interacted with BamNx and the inactivation might be the result of formation of a binary complex. The inhibitory activity was sensitive to treatment with trypsin. The molecular weight of the inhibitor protein was estimated to be approximately 20,000 daltons by gel filtration.
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D001435:Bacteriophages / Q000235:genetics*; D004262:DNA Restriction Enzymes / Q000037:antagonists & inhibitors*; D008970:Molecular Weight; D009154:Mutation; D014764:Viral Proteins / Q000032:analysis / Q000235:genetics*
chemical_list: D014764:Viral Proteins; D004262:DNA Restriction Enzymes