Search PubMed⌕ Search

Biomedical subjects

M Meselson

Publications and source records attributed to M Meselson.

54 records · Page 3Linked to original sources
PubMed1972

DNA modification methylase activity of Escherichia coli restriction endonucleases K and P.

The highly purified restriction endonucleases of E. coli K and coliphage P1 transfer methyl groups from S-adenosylmethionine to adenine residues of unmodified DNA. Incubation of unmodified DNA with endonucleases K or P and S-adenosylmethionine renders the DNA resistant to restriction. The enzymes, therefore, have both restriction endonuclease and modification methylase activities.

Chromatography, DEAE-Cellulose↗
PubMed1970

Topological relationship of prophage lambda to the bacterial chromosome in lysogenic cells.

X irradiation converts bacterial sex factor DNA covalent circles to more slowly sedimenting forms according to first order kinetics. The rate of conversion is greater for sex factors carrying lambda prophage than it is for nonlysogenized sex factors. The magnitude of the difference and the absence of covalent circular DNA from the product show that the prophage DNA is linearly inserted into the sex factor, as predicted by Campbell's model for lysogenization.

Centrifugation, Density Gradient↗
PubMed1970

A T4-induced endonuclease which attacks T4 DNA.

A DNA endonucleolytic activity that introduces single-stranded breaks into native T4 DNA is found in T4-infected E. coli. This endonuclease attacks other double-stranded, but not single-stranded, DNA. Experiments with ultraviolet-irradiated phages and amber mutants indicate that the enzyme is made beginning about five minutes after infection at 37 degrees C.

Centrifugation, Density Gradient↗