RNA-linked nascent DNA pieces in T7 phage-infected Escherichia coli cells. I. Role of gene 6 exonuclease in removal of the linked RNA.
The presence of RNA-linked nascent DNA pieces in T7 phage-infected Escherichia coli cells has been shown by the selective degradation of the 5'-hydroxyl-terminated nascent DNA, produced by alkali or RNase treatment, with spleen exonuclease. At 43 degrees C, the proportion of RNA-linked DNA pieces in nascent short dna is 50 to 60% in T7 ts136 (ts mutant of gene 6) phage-infected E. coli, whereas that in T7 wild-type phage-infected cells is less than 6%. Joining of the nascent pieces is greatly retarded in T7 ts136-infected E. coli temperature sensitive polA mutants at 43 degrees C. These results suggest that gene 6 exonuclease plays a role in removal of the linked RNA during the discontinuous replication of T7 DNA.
D000818:Animals; D002499:Centrifugation, Density Gradient; D003090:Coliphages / Q000378:metabolism*; D004261:DNA Replication; D004279:DNA, Viral / Q000378:metabolism*; D004926:Escherichia coli; D005092:Exonucleases / Q000494:pharmacology*; D005814:Genes, Viral; D006358:Hot Temperature; D009154:Mutation; D012367:RNA, Viral / Q000378:metabolism*; D013552:Swine
D004279:DNA, Viral; D012367:RNA, Viral; D005092:Exonucleases