Partial purification of the Escherichia coli K-12 mec+ deoxyribonucleic acid-cytosine methylase: in vitro methylation completely protects bacteriophage lambda deoxyribonucleic acid against cleavage by R-EcoRII
Open Access
- 1 March 1977
- journal article
- research article
- Published by American Society for Microbiology in Journal of Bacteriology
- Vol. 129 (3), 1330-1334
- https://doi.org/10.1128/jb.129.3.1330-1334.1977
Abstract
A procedure is described for the partial purification of the deoxyribonucleic acid (DNA)-cytosine methylases controlled by the RII plasmid and by the Escherichia coli mec+ gene. The two enzymes exhibit similar but distinct chromatographic behavior on diethylaminoethyl-cellulose and phosphocellulose. Preliminary studies on the two methylases indicate that they are indistinguishable with respect to their Km for S-adenosylmethionine and their pH (in tris (hydroxymethyl)aminomethane buffer) and NaCl concentration optima. In vitro methylation of various phage lambda DNA substrates by the mec9r RII enzyme modifies the DNA to a form that is completely resistant to double-stranded cleavage by the RII restriction endonuclease (R-EcoRII). These results are consistent with our earlier proposal that the mec8ethylase recognizes RII host specificity sites.This publication has 19 references indexed in Scilit:
- The sensitivity of bacteriophage lambda DNA to restriction endonuclease RIIJournal of Molecular Biology, 1975
- Endonuclease R-EcoRII restriction of bacteriophage f1 DNA in vitro: ordering of genes V and VII, location of an RNA promotor for gene VIIIJournal of Virology, 1975
- Mutants of the N-3 R-Factor Conditionally Defective in hsp II Modification and Deoxyribonucleic Acid-Cytosine Methylase ActivityJournal of Bacteriology, 1974
- DNA Substrate Site for the EcoRII. Restriction Endonuclease and Modification MethylaseNature New Biology, 1973
- Isolation of Deoxyribonucleic Acid Methylase Mutants of Escherichia coli K-12Journal of Bacteriology, 1973
- Isolation of a Mutant of Escherichia coli Defective in Cytosine-Specific Deoxyribonucleic Acid Methylase Activity and in Partial Protection of Bacteriophage λ Against Restriction by Cells Containing the N-3 Drug-Resistance FactorJournal of Bacteriology, 1973
- DNA Methylases of Escherichia coli K12European Journal of Biochemistry, 1972
- Methylation of Cytosine Residues in DNA Controlled by a Drug Resistance FactorProceedings of the National Academy of Sciences, 1972
- On the Nature of the Deoxyribonucleic Acid Methylases. Biological Evidence for the Multiple Nature of the Enzymes*Biochemistry, 1965
- The Enzymatic Methylation of Ribonucleic Acid and Deoxyribonucleic AcidPublished by Elsevier ,1964