title: Repair replication in permeabilized Escherichia coli.
abstract: We have examined the modes of DNA synthesis in Escherichia coli strains made permeable to nucleoside triphosphates by treatment with toluene. In this quasi in vitro system, polymerase-I-deficient mutants exhibit a nonconservative mode of synthesis with properties expected for the resynthesis step of excision-repair. This UV-stimulated DNA synthesis can be performed by either DNA polymerase II or III and it also requires the uvrA gene product. It requires the four deoxynucleoside triphosphates; but, in contrast to the semiconservative mode, the ATP requirement can be partially satisfied by other nucleoside triphosphates. The ATP-dependent recBC nuclease is not involved. The observed UV-stimulated mode of DNA synthesis may be part of an alternate excision-repair mechanism which supplements or complements DNA-polymerase-I-dependent repair in vivo.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D004254:DNA Nucleotidyltransferases / Q000378:metabolism; D004260:DNA Repair; D004261:DNA Replication; D004926:Escherichia coli / Q000378:metabolism* / Q000528:radiation effects; D009154:Mutation; D011830:Radiation Effects; D013045:Species Specificity; D013941:Thymine / Q000378:metabolism; D014466:Ultraviolet Rays
chemical_list: D000255:Adenosine Triphosphate; D004254:DNA Nucleotidyltransferases; D013941:Thymine