title: Purification and properties of two deoxyribonucleases of Pseudomonas aeruginosa.
abstract: A survey of the major deoxyribonucleases in Pseudomonas aeruginosa strain PAO was undertaken. Two activities predominated in Brij-58 lysates of this organism. These have been purified from contaminating nuclease activities, and some of their properties have been elucidated. The first was a nuclease that degraded heat-denatured deoxyribonucleic acid (DNA) to mono- and dinucleotides. The activity of this enzyme was confined to single-stranded DNA, and 100% of the substrate was hydrolyzed to acid-soluble material. The Mg2+ optimum is low (1 to 3mM), and the molecular weight is 6 X 10(4). The second predominant activity was an adenosine 5'-triphosphate (ATP)-dependent deoxyribonuclease. This enzyme had an absolute dependence on the presence of ATP Mg2+ concentrations of approximately 10 mM. Five moles of ATP was consumed for each mole of phosphodiester bonds cleaved. The acid-soluble products of the reaction consisted of short oligonucleotides from one to six bases in length. Only 50% of the double-stranded DNA was rendered acid soluble in a limit digest. The molecular weight of this enzyme is 3 X 10(5). The observation of these enzymes in P. aeruginosa is consistent with the possibility that recombinational pathways similar to those of Escherichia coli are operating in this organism.
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D011232:Chemical Precipitation; D002845:Chromatography; D004269:DNA, Bacterial / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D003851:Deoxyribonucleases / Q000302:isolation & purification / Q000378:metabolism; D004096:Dihydrostreptomycin Sulfate; D005092:Exonucleases / Q000302:isolation & purification / Q000378:metabolism; D006358:Hot Temperature; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight; D009691:Nucleic Acid Denaturation; D011550:Pseudomonas aeruginosa / Q000201:enzymology*
chemical_list: D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D000255:Adenosine Triphosphate; D003851:Deoxyribonucleases; D005092:Exonucleases; D008274:Magnesium; D004096:Dihydrostreptomycin Sulfate