title: ATP hydrolysis during SOS induction in Escherichia coli.
abstract: Changes in cellular ATP concentration during SOS induction in strains of Escherichia coli with different levels of RecA and LexA proteins were studied. UV irradiation of RecA+ strains induced a twofold increase in the ATP concentration around the first 20 min, followed by a decrease to the values of nonirradiated cells. On the other hand, mutants defective in RecA protein or with either deficient RecA protease activity or cleavage-resistant LexA repressor did not show any decrease, suggesting that ATP consumption is related to LexA repressor hydrolysis. Furthermore, strains presenting a constitutive synthesis of RecA protein showed the same changes in ATP concentration as the wild-type strain. Likewise, the presence in a RecA+ strain of a LexA(Def) protein, which is defective in its capacity for binding specifically to SOS operators, did not disturb the changes in ATP when compared with the LexA+ RecA+ strain. Moreover, after UV irradiation, a LexA(Def) RecA- double mutant showed an important increase in ATP concentration, which remained elevated for at least 120 min after UV treatment.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004260:DNA Repair; D004926:Escherichia coli / Q000378:metabolism* / Q000528:radiation effects; D005786:Gene Expression Regulation; D006868:Hydrolysis; D011938:Rec A Recombinases / Q000235:genetics / Q000378:metabolism; D012697:Serine Endopeptidases; D014466:Ultraviolet Rays; D000099160:LexA Repressor Protein
chemical_list: D000255:Adenosine Triphosphate; D001426:Bacterial Proteins; D011938:Rec A Recombinases; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein