title: The EcoDXX1 restriction and modification system of Escherichia coli ET7. Purification, subunit structure and properties of the restriction endonuclease.
abstract: The Escherichia coli plasmid pDXX1 codes for a new restriction-modification system. The specific restriction endonuclease coded by this system has been purified by a procedure that includes phosphocellulose and heparin-agarose chromatography. Sedimentation on glycerol gradients showed one peak of activity with a value of about 12 S. The highly purified enzyme require ATP and Mg2+ for activity as well as S-adenosylmethionine, although some S-adenosylmethionine molecules are probably bound to the enzyme. The enzyme does not cleave lambda DNA at well-defined sites and has a strong non-modified DNA-dependent ATPase activity. The enzyme has also methylase activity acting against non-modified DNA.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D055598:Chemical Phenomena; D002621:Chemistry; D003067:Coenzymes / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000235:genetics / Q000302:isolation & purification*; D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial / Q000378:metabolism; D004586:Electrophoresis / Q000379:methods; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D008780:Methyltransferases / Q000235:genetics / Q000302:isolation & purification*; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000032:analysis; D010957:Plasmids; D013696:Temperature
chemical_list: D003067:Coenzymes; D015280:DNA Restriction-Modification Enzymes; D004269:DNA, Bacterial; D010446:Peptide Fragments; D008780:Methyltransferases; D004248:DNA (Cytosine-5-)-Methyltransferases; D004262:DNA Restriction Enzymes; C046915:endodeoxyribonuclease EcoDXXI; D000251:Adenosine Triphosphatases