Partial Purification and Characterization of Restriction Endonuclease from Neisseria meningitidis

摘要

A restriction endonuclease, NmeI, present in Neisseria meningitidis DRES W34 was studied. The enzyme was partially purified by passing through a blue 2 cross-linked agarose column; no contaminating nucleases remained detectable. This enzyme cleaved phage lambda, adenovirus type 2 (Ad 2) and phi x 174 DNA but did not cleave simian virus 40 (SV40) DNA. It had an absolute requirement for Mg(2+) for its activity and was inhibited by high concentrations of sodium chloride or magnesium chloride. NmeI activity was completely abolished after one hour of incubation at 65 C. S-adenosyl-L-methionine and ATP had no effect on its activity suggesting that NmeI is a type II restriction endonuclease enzyme.