title: A Salmonella typhimurium endonuclease that converts native DNA to fragments of about 8 X 10(5) daltons.
abstract: Crude extracts of Salmonella typhimurium were found to contain an endonuclease that degraded double-stranded linear DNA from bacteria and phages to fragments with a molecular weight of about 8 X 10(5). The nuclease did not have an absolute requirement for Mg2+. One discrete intermediate product had a molecular weight of 6-6 X 10(6). Extracts from two different mutants were tested: one completely lacked the endonuclease activity (strain DB5575), and the other showed an absolute requirement for Mg2+ (strain 4543). No biological role has yet been found for this endonuclease of S. typhimurium.
mesh_terms: D001435:Bacteriophages; D004262:DNA Restriction Enzymes / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism*; D004720:Endonucleases / Q000378:metabolism*; D008274:Magnesium; D008970:Molecular Weight; D009154:Mutation; D012486:Salmonella typhimurium / Q000201:enzymology*
chemical_list: D004279:DNA, Viral; D004720:Endonucleases; D004262:DNA Restriction Enzymes; D008274:Magnesium