The genetic dependence of RecBCD-Gam mediated double strand end repair in Escherichia coli.
The repair of double strand breaks after gamma-irradiation in wild-type Escherichia coli lysogenic for lambda cI857 red3 is more efficient when lambda Gam protein is present. This phenomenon, called gam dependent radioresistance, requires the interaction of RecBCD enzyme and Gam protein. We compared cell survival after gamma-irradiation in wild-type and mutant lysogens with and without induction of Gam by transient heat treatment of the cells (6 min, 42 degrees C). The main conclusions are: (1) the RecBCD-Gam pathway of recombination repair is similar but not equivalent to RecBCD, a pathway operating in recD mutants; (2) the RecBCD-Gam pathway is dependent on recJ, recQ and recN gene products and it is proposed that the RecBCD-Gam complex has ability to load RecA protein onto single strand DNA.
Paskvan
I
I
Department of Molecular Genetics, RuderBoskovic Institute, P.O.B. 180, 10002, Zagreb, Croatia.
Salaj-Smic
E
E
Ivancic-Baće
I
I
Zahradka
K
K
Trgovcević
Z
Z
Brcić-Kostić
K
K
D000251:Adenosine Triphosphatases / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D004265:DNA Helicases / Q000235:genetics; D004260:DNA Repair; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D003851:Deoxyribonucleases / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics* / Q000528:radiation effects; D029968:Escherichia coli Proteins; D043211:Exodeoxyribonuclease V; D005090:Exodeoxyribonucleases / Q000235:genetics*; D005720:Gamma Rays; D009154:Mutation; D011485:Protein Binding; D053484:RecQ Helicases; D011995:Recombination, Genetic; D014764:Viral Proteins / Q000235:genetics*
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D014764:Viral Proteins; C065410:gam protein, Coliphage; D003851:Deoxyribonucleases; D005090:Exodeoxyribonucleases; C489467:RecJ protein, E coli; C070765:recJ protein, Bacteria; D043211:Exodeoxyribonuclease V; C468322:exodeoxyribonuclease V, E coli; D004262:DNA Restriction Enzymes; C047879:RecN protein, Bacteria; D000251:Adenosine Triphosphatases; C506724:RecQ protein, E coli; D004265:DNA Helicases; D053484:RecQ Helicases