title: [Weakening of bacteriophage lambda EcoK DNA restriction in the presence of plasmid pKM101 ard+. I. General characteristics and genetic localization].
abstract: The host-controlled K-restriction of unmodified phage lambda is ten to hundred-fold alleviated in the E. coli K12 strain, carring plasmid pKM101 of N-incompatibility group. By restriction mapping Tn5 insertion in pKM101, which reduced pKM101-mediated alleviation of K-restriction, was shown to by located within BglII-B-fragment approximately 9 kb anticlockwise from the EcoRI-site of pKM101. We have termed the gene(s) promoting the alleviation of K-restriction ARD (Alleviation of Restriction of DNA). It was shown that (i) plasmid pKM101-mediated alleviation of K-restriction did not depend on bacterial genes LexA, RecBC, umuC and plasmid gene muc; (ii) ard gene did not mediate EcoK type modification of DNA and did not enhance the modification activity of EcoK system in a way similar to that observed with RAL gene of phage lambda. Action of Ard gene of plasmid pKM101 is highly specific: alleviation of restriction of DNA lambda takes place only in K-strains of E. coli and is practically absent in B-strains and also in E. coli strains which have restricting enzymes of 11 type, EcoRI and EcoRIII.
mesh_terms: D010582:Bacteriophage lambda / Q000235:genetics*; D002874:Chromosome Mapping; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000235:genetics; D004279:DNA, Viral / Q000235:genetics; D015253:Deoxyribonucleases, Type I Site-Specific; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005798:Genes, Bacterial; D005819:Genetic Markers; D009154:Mutation; D010641:Phenotype; D010957:Plasmids
chemical_list: D004269:DNA, Bacterial; D004279:DNA, Viral; D005819:Genetic Markers; D004262:DNA Restriction Enzymes; C029602:endodeoxyribonuclease EcoK; D015253:Deoxyribonucleases, Type I Site-Specific
vernacular_title: Oslablenie restriktsii EcoK DNK bakteriofaga lambda v prisutstvii plazmidy pKM101 ard+. I. Obshchaia kharakteristika i geneticheskaia lokalizatsiia.