Inhibition of RNase II by DNA

Gorelic, Lester; Apirion, David

doi:10.1016/s0006-291x(71)80211-5

Cited by 11 publications

(3 citation statements)

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“…The reported inhibition of ribonuclease II by oligodeoxyribonucleotides present in extracts (Gorelic & Apirion, 1971) was not found in the extracts used in these experiments. Fig.…”

Section: Resultsmentioning

confidence: 59%

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The role of ribonuclease II in the maturation of precursor 16S ribosomal ribonucleic acid in Escherichia coli

Dean

Sykes

1974

Biochemical Journal

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The suggested involvement of ribonuclease II in the maturation of rRNA has been examined directly by determining the activity of the enzyme and the amount of p16S rRNA in cell-free extracts from Escherichia coli A19 and its temperature-sensitive derivative N464 grown under experimental conditions designed to vary the amounts of enzyme and precursor independently. In strain A19 the enzyme showed maximum activity in circumstances where the amount of p16S rRNA was normal (e.g. exponential-phase cells) or raised eight times (e.g. during inhibition of growth by methionine starvation of the relaxed auxotroph or by chloramphenicol or puromycin treatment). In strain N464 at the non-permissive temperature the ribonuclease II activity may be decreased by 50% without effect upon the amount of p16S rRNA, whereas in methionine starvation of this strain the enzyme activity is at a maximum and the p16S rRNA is eight times that in exponential-phase cells. These observations are discussed in relation to the previously implied role of ribonuclease II in the maturation of rRNA within ribosome precursors.

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“…The reported inhibition of ribonuclease II by oligodeoxyribonucleotides present in extracts (Gorelic & Apirion, 1971) was not found in the extracts used in these experiments. Fig.…”

Section: Resultsmentioning

confidence: 59%

“…ribonuclease I (Spahr, 1964;Datta & Burma, 1972), and (iii) the presence of inhibitors in the extract, e.g. oligodeoxyribonucleotides inhibiting the enzyme (Gorelic & Apirion, 1971) or ribosomes binding and protecting the substrate (Castles & Singer, 1969).…”

Section: Resultsmentioning

confidence: 99%

The role of ribonuclease II in the maturation of precursor 16S ribosomal ribonucleic acid in Escherichia coli

Dean

Sykes

1974

Biochemical Journal

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“…Later, we found that DNA oligonucleotides inhibit the RNase II activity of cell extracts, as well as purified RNase II (9). However, the difference in RNase II acitivity between extracts of the RNase+ and the RNase hyper strain can be observed whether or not they are treated with DNase$.…”

Section: Resultsmentioning

confidence: 98%

An Escherichia coli Mutant with Increased Messenger Ribonuclease Activity

Lennette

Gorelic

Apirion

1971

Proc. Natl. Acad. Sci. U.S.A.

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A temperature-sensitive mutant strain of Escherichia coli exhibits a remarkable increase in RNase activity when grown at its nonpermissive temperature. During growth at the nonpermissive temperature, there is an increase in the extent of breakdown of pulse-labeled RNA and a decrease in the functional lifetime of the mRNA for the lac operon. T7 RNA, which is usually stable in E. coli, is also stable in this strain at the nonpermissive temperature. It is possible that the RNase measured is part of the normal mechanism of mRNA degradation in the cell. A mechanism for mRNA degradation that requires the combined action of endonuclease(s) and 3' to 5' exonuclease(s) is proposed.An understanding of the mechanism by which mRNA is degraded could be useful for the analysis of a number of fundamental cellular processes. In order to study these mechanisms, we have been trying to isolate mutant strains modified in mRNase activity and to identify the altered enzymes. Assuming that an enzyme with mRNase activity is indispensable for normal growth, we had to resort to the isolation of conditional-lethal mutants. One procedure is to look for RNase-less strains among a collection of temperature-sensitive mutants. A disadvantage of this approach is that if a reduced level of a given RNase is not accompanied by significant alteration in mRNA lifetime, it is possible that the enzyme is present in the cell, but is unstable and destroyed during preparation of extracts. Therefore, we chose instead to look for mutants with increased RNase activity at a high temperature among a collection of temperature-sensitive mutants. It seemed possible that if the increased activity were involved in mRNA breakdown, certain readily identifiable physiological consequences could follow, e.g., a reduction in functional lifetime of mRNA.Recently we isolated a class of temperature-sensitive mutants of Escherichia coli that show an increased sensitivity to starvation, (designated sts mutants, starvation-temperature sensitive, refs. 1 and 2). These mutants are temperature sensitive (grow at 300C but not at 430C) and cannot recover from glucose starvation. Among the members of this class, we identified strains altered in the ability to synthesize proteins due to defects in ribosomal (1, 2) as well as in supernatant components (3). Since mRNA synthesis is reduced during starvation (4), it seemed reasonable to assume that strains with increased mRNase activity might have insufficient mRNA for necessary turnover processes and would fail to recover from a period of extended starvation. Therefore, we tested sonicates of 150 such sts strains in a standard assay for RNase II (5) at 300 and 430C. This assay was chosen because of its simplicity and because RNase II has already been implicated in mRNA breakdown in E. coli (6). We found eight strains with an increased RNase activity. The studies reported here were done with one of these strains, designated N4752. Our studies suggest that mRNA degradation is altered in strain N4752. RESULTS Strains, growth, and ...

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RNA precursor molecules and ribonucleases in E. coli

Altman¹,

Robertson²

1973

Mol Cell Biochem

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Inhibition of RNase II by DNA

Cited by 11 publications

References 10 publications

The role of ribonuclease II in the maturation of precursor 16S ribosomal ribonucleic acid in Escherichia coli

The role of ribonuclease II in the maturation of precursor 16S ribosomal ribonucleic acid in Escherichia coli

An Escherichia coli Mutant with Increased Messenger Ribonuclease Activity

RNA precursor molecules and ribonucleases in E. coli

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