Mutants of Escherichia coli Lacking Endonuclease I, Ribonuclease I, or Ribonuclease II

Mutants of Escherichia coli lacking endonuclease I, ribonuclease I, or ribonuclease II.

To isolate mutants of Escherichia coli K-12 lacking endonuclease I activity (end), a method has been developed which detects, by differential methyl green staining, undegraded deoxyribonucleic acid (DNA) in colonies previously incubated in toluene. This procedure allows isolation of mutant strains in which DNA degradation is reduced. For half of these strains, this defect has been correlated wi...

Screening procedure for Escherichia coli mutants deficient in ribonuclease I.

Strains of Escherichia coli that possess ribonucleic acid accumulated under relaxed growth conditions show a considerable increase in time before the onset of beta-galactosidase inducibility. This time dependency can be related to the presence or absence of ribonuclease I.

Inhibition of ribonuclease I in Escherichia coli by polymyxin B.

The "latent" RNase I of E. coli ribosomes is avtivated by polymyxins in media containing enough magnesium (10~4 to 1 0 3 M) to prevent RNase Iinduced autolysis of ribosomal RNA under normal conditions 2. On the other side RNase I-induced RNA depolymerization in membrane injured cells of E. coli is inhibited by polymyxin B in EDTA containing buffers 3. The following communication presents some m...

Genetic locus for ribonuclease I in Escherichia coli.

Purification and Properties of Ribonuclease Ii from Escherichia Coli.

Three enzymes in Escherichia coli which break down ribonucleic acid are now known. One is polynucleotide phosphorylase (I), which in the presence of phosphate yields ribonucleoside 5’-diphosphates. A ribonuclease, which will be called ribonuclease I, is bound to 30 S ribosomes in latent form. When released from the ribosomes it attacks RNA to yield ribonucleoside 3’-phosphates via a 2’) 3’-cycl...