title: Purification and properties of a new restriction endonuclease from Haemophilus influenzae Rf.
abstract: Haemophilus influenzae Rf 232, showing the phenomena of restriction and modification, contains an endonuclease that inactivates in vitro the biological activity of DNAs lacking the strain-specific modification. This specific restriction endonuclease has been purified to near homogeneity by a procedure that includes DNA-agarose chromatography. This highly purified enzyme requires ATP and Mg2+ for activity and is stimulated by S-adenosylmethionine. The enzyme seems to cleave DNA at well-defined sites, since it produces a specific pattern of bands upon agarose gel electrophoresis. The enzyme has no ATPase activity. A methylase activity is observed in the course of the endonucleolytic reaction, which probably protects some of the DNA sites from cleavage.
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000494:pharmacology; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000378:metabolism; D004262:DNA Restriction Enzymes / Q000302:isolation & purification / Q000378:metabolism*; D006193:Haemophilus influenzae / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000494:pharmacology; D008970:Molecular Weight; D009994:Osmolar Concentration; D012436:S-Adenosylmethionine / Q000494:pharmacology; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D012436:S-Adenosylmethionine; D000255:Adenosine Triphosphate; D004248:DNA (Cytosine-5-)-Methyltransferases; D004262:DNA Restriction Enzymes; D000251:Adenosine Triphosphatases; D008274:Magnesium