title: The ocr gene function of bacterial viruses T3 and T7 prevents host-controlled modification.
abstract: On pre-infection of the host Escherichia coli B with u.v.-inactivated T3 or T7 phage able to express their early genes (like 0.3), B-specific modification of superinfecting, successfully multiplying viruses does not take place. The ocr gene function (gene 0.3) of T3 and T7 not only prevents host-specific DNA restriction but also modification, probably by inhibiting the same late step in the interaction between the restriction enzyme and DNA.
mesh_terms: D003090:Coliphages / Q000235:genetics* / Q000254:growth & development; D004262:DNA Restriction Enzymes / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D005814:Genes, Viral; D009154:Mutation
chemical_list: D004279:DNA, Viral; D004262:DNA Restriction Enzymes