title: DNA restriction and modification in Escherichia coli: functional analysis of the role of the dnaC(D) gene product.
abstract: Escherichia coli strain PC-7 carries two independent temperature-sensitive mutations, one affecting the restriction and modification (R-M) phenotype and the other the DnaC(D) phenotype. The results of complementation and P1 transduction analysis of the mutation affecting the R-M phenotype implicate a fourth gene, designated hsdX, located close to the hsd three-gene complex. The properties of merodiploids constructed between appropriate recipients and F' elements with different mutations in hsdS, hsdR and hsdM genes might indicate that in strain PC-7 the temperature-sensitive products, determined by hsdR and hsdSK cistrons, are synthesized. The role of the temperature-sensitive dnaC(D) gene product in the formation of the restriction endonuclease was studied and no direct relation was found between the DnaC(D) and R-M phenotypes.
mesh_terms: D004261:DNA Replication; D004262:DNA Restriction Enzymes / Q000096:biosynthesis / Q000235:genetics*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D005809:Genes, Regulator; D005816:Genetic Complementation Test; D009154:Mutation; D014161:Transduction, Genetic
chemical_list: D004262:DNA Restriction Enzymes