Molecular cloning and characterization of a genetic region from Serratia marcescens involved in DNA repair.
We report here the molecular isolation of a DNA fragment which encodes Tag-like activity from the Gram-negative bacterium Serratia marcescens. A recombinant plasmid encoding Tag-like activity was isolated from a S. marcescens plasmid gene library by complementation of an Escherichia coli tag mutant, which is deficient in 3-methyladenine DNA glycosylase I. The clone complements E. coli tag, recA, alkA, but not alkB, mutants for resistance to the DNA-damaging agent methyl methanesulphonate (MMS). The coding region of the Tag activity, initially isolated on a 6.5kb BamHI fragment, was defined to a 1.8kb BglII-SmaI fragment. Labelling of plasmid-encoded proteins using maxicells revealed that the 1.8kb fragment encodes two proteins of molecular weights 42,000 and 16,000. Data presented here suggest that the cloned fragment encodes a DNA repair protein(s) that has similar activity to the 3-methyladenine DNA glycosylase I of E. coli.
Murphy
K E
KE
Programme in Genetics, Louisiana State University, Baton Rouge 70803.
Braymer
H D
HD
D003001:Cloning, Molecular; D045647:DNA Glycosylases; D004260:DNA Repair; D004269:DNA, Bacterial / Q000235:genetics*; D005816:Genetic Complementation Test; D008741:Methyl Methanesulfonate / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008970:Molecular Weight; D009154:Mutation; D009699:N-Glycosyl Hydrolases / Q000235:genetics* / Q000378:metabolism; D010957:Plasmids; D011938:Rec A Recombinases / Q000235:genetics; D015183:Restriction Mapping; D012706:Serratia marcescens / Q000235:genetics*
D004269:DNA, Bacterial; D008741:Methyl Methanesulfonate; D011938:Rec A Recombinases; C021565:3-methyladenine-DNA glycosylase; D045647:DNA Glycosylases; D009699:N-Glycosyl Hydrolases