Title

Isolation of deoxyribonucleic acid methylase mutants of Escherichia coli K-12

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Publication Date

1973-06-01

Document Type

Article

Subjects

Chromosome Mapping; Coliphages; Culture Media; DNA, Bacterial; Escherichia coli; Hydrolysis; Methyltransferases; Mutation; Nitrosoguanidines

Disciplines

Biochemistry, Biophysics, and Structural Biology

Abstract

Fourteen deoxyribonucleic acid (DNA) and 10 ribonucleic acid (RNA) methylation mutants were isolated from Escherichia coli K-12 by examining the ability of nucleic acids prepared from clones of unselected mutagenized cells to accept methyl groups from wild-type crude extract. Eleven of the DNA methylation mutants were deficient in 5-methylcytosine (5-MeC) and were designated Dcm. Three DNA methylation mutants were deficient in N(6)-methyladenine (N(6)-MeA) and were designated Dam. Extracts of the mutants were tested for DNA-cytosine:S-adenosylmethionine and DNA-adenine:S-adenosylmethionine methyltransferase activities. With one exception, all of the mutants had reduced or absent activity. A representative Dcm mutation was located at 36 to 37 min and a representative Dam mutation was located in the 60-to 66-min region on the genetic map. The Dcm mutants had no obvious associated phenotypic abnormality. The Dam mutants were defective in their ability to restrict lambda. None of the mutations had the effect of being lethal.

Source

J Bacteriol. 1973 Jun;114(3):1143-50.

Journal/Book/Conference Title

Journal of bacteriology

Related Resources

Link to Article in PubMed

PubMed ID

4576399

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