Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.26.5 (RNase P)
1,348 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. A precursor to small stable RNA, 10Sa RNA, accumulates in large amounts in a temperature sensitive RNase E mutant at non-permissive temperatures, and somewhat in an rnc (RNase III-) mutant, but not in an RNase P- mutant (rnp) or wild type E. coli cells. 2. Since p10Sa RNA was not processed by purified RNase E and III in customary assay conditions, we purified p10Sa RNA processing activity about 700-fold from wild type E. coli cells. 3. Processing of p10Sa RNA by this enzyme shows an absolute requirement for a divalent cation with a strong preference for Mn2+ over Mg2+. Other divalent cations could not replace Mn2+. 4. Monovalent cations (NH+4, Na+, K+) at a concentration of 20 mM stimulated the processing of p10Sa RNA and a temperature of 37 degrees C and pH range of 6.8-8.2 were found to be optimal. 5. The enzyme retained half of its p10Sa RNA processing activity after 30 min incubation at 50 degrees C. 6. Further characterization of this activity indicated that it is RNase III. 7. To further confirm that the p10Sa RNA processing activity is RNase III, we overexpressed the RNase III gene in an E. coli cells that lacks RNase III activity (rnc mutant) and RNase III was purified using one affinity column, agarose.poly(I).poly(C). 8. This RNase III preparation processed p10Sa RNA in a similar way as observed using the p10Sa RNA processing activity purified from wild type E. coli cells, confirming that the first step of p10Sa RNA processing is carried out by RNase III.
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PMID:Characterization of the RNA processing enzyme RNase III from wild type and overexpressing Escherichia coli cells in processing natural RNA substrates. 137 63

We recently showed that RNase III can process a small stable RNA, precursor 10Sa RNA, that accumulates in an rne (RNase E) strain at non-permissive temperatures. Precursor 10Sa (p10Sa) RNA is processed to 10Sa RNA in two steps, the first step is catalyzed by RNase III in the presence of Mn2+ but not Mg2+. It was shown that RNase III cosediments with membrane preparation from wild type as well as RNase III overexpressing cells. However, the possibility of membrane preparation contamination with ribosomes could not be ruled out. Here we show that RNase III, E and P are not associated with ribosomes. E. coli cells were opened either by alumina grinding or by sonication and fractionated into cytosolic and pellet fractions. The characterization of membrane preparations was done by assaying NADH oxidase, a bona fide membrane enzyme. Ribosomes prepared by alumina grinding were found to be contaminated with small fragments of membrane which contained RNase III activity. RNase III and NADH oxidase activities were present in the ribosomal preparations which could be solubilized by reagents that dissolve the inner membrane. Isopycnic sucrose gradient centrifugation of the membrane and ribosomal preparations also confirmed that RNase III fractionated with the inner membrane. Similarly RNase P activity was found in the corresponding fractions when isopycnic centrifugation of membrane and ribosome preparations was carried out. RNase E activity was also found to be present mostly in the post-ribosomal supernatant. These findings show that RNase III, E and P are not ribosomal enzymes.
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PMID:RNA processing enzymes RNase III, E and P in Escherichia coli are not ribosomal enzymes. 172 76

Cells overexpressing the RNA-processing enzymes RNase III, RNase E and RNase P were fractionated into membrane and cytoplasm. The RNA-processing enzymes were associated with the membrane fraction. The membrane was further separated to inner and outer membrane and the three RNA-processing enzymes were found in the inner membrane fraction. By assaying for these enzymatic activities we showed that even in a normal wild-type strain of Escherichia coli these enzymes fractionate primarily with the membrane. The RNA part of RNase P is found in the cytosolic fraction of cells overexpressing this RNA, while the overexpressed RNase P protein sediments with the membrane fraction; this suggests that the RNase P protein anchors the RNA catalytic moiety of the enzyme to a larger entity. The implications of these findings for the cellular organization of the RNA-processing enzymes in the cell are discussed.
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PMID:Location of the RNA-processing enzymes RNase III, RNase E and RNase P in the Escherichia coli cell. 194 11

The splice junction sequence of td mRNA from T4-infected cells has been determined (5'....GGU-CUA....3') and shown to be identical to that of the RNA ligation product encoded by the cloned gene [Belfort et al. Cell 41 (1985) 375-382]. The RNA processing functions, T4 RNA ligase, T4 polynucleotide kinase, and the host prr gene product appear not to be essential for exon ligation; neither are the host endoribonucleases RNase III, RNase P and RNase E required for intron excision. While these results are consistent with the autocatalytic splicing mechanism demonstrated in vitro [Chu et al. J. Biol. Chem. 260 (1985) 10680-10688], they leave unanswered the question of which protein(s), if any, might stimulate the in vivo reaction. Analysis of the products of the cloned td gene has led to identification of two td-encoded polypeptides, namely a polypeptide corresponding to the exon-I-coding sequence (NH2-TS), and the catalytically active thymidylate synthase (TS). Kinetic and nucleotide sequence data provide evidence that NH2-TS is the product of the primary transcript and that TS is encoded by spliced mRNA. These results suggest that splicing may provide a switch controlling the relative expression of NH2-TS and TS, two proteins with markedly different temporal appearances despite their identical transcriptional and translational start sites.
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PMID:RNA splicing and in vivo expression of the intron-containing td gene of bacteriophage T4. 242 90

The bla and ompA gene transcripts were used as substrates to probe Escherichia coli extracts for ribonucleolytic activities. A site specific endoribonucleolytic activity was identified that cleaves ompA and bla mRNA. The cleavages occur in vitro and in vivo. For both the bla and ompA mRNA most of the cleavage sites which were identified map in the 5' non-coding region. The cleavages of the ompA transcript have been previously suggested to regulate the growth rate dependent stability of this mRNA. Thus we propose that the identified endoribonucleolytic activity may be involved in the degradation of mRNA. Analysis of mutants revealed that the cleavages are mediated by endonucleases which do not seem to be identical to RNase III, RNase E or RNase P.
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PMID:In vivo and in vitro identity of site specific cleavages in the 5' non-coding region of ompA and bla mRNA in Escherichia coli. 304 39

Stability of RNA was tested in strains of Escherichia coli carrying single, double, or triple mutations in the RNA processing enzymes RNase III, RNase E and RNase P. Tests were carried out for total pulse labeled RNA, beta-galactosidase mRNA and for the decay of preexisting RNA during carbon starvation. Decay of RNA was measured at permissive and nonpermissive temperatures, and in no case were significant differences between mutants and non-mutant strains found. Therefore, we conclude that the three processing enzymes; RNase III, E and P do not contribute significantly to turnover of RNA IN Escherichia coli.
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PMID:Decay of RNA in RNA processing mutants of Escherichia coli. 615 28

A precursor molecule for 10Sb (M1) RNA, the RNA moiety of the RNA processing enzyme ribonuclease P (EC 3.1.26.5), is accumulated transiently in an Escherichia coli strain containing a plasmid that carries the 10Sb RNA gene. The same RNA precursor molecule is accumulated, in relatively large quantities, in a temperature-sensitive RNase E- mutant at the nonpermissive temperature. The RNA precursor includes 10Sb RNA and an extra 3' fragment that contains a termination stem and loop. It can be processed in vitro to a molecule the size of 10Sb RNA. None of the four endoribonucleases of E. coli--RNase III, RNase E, RNase F, or RNase P--takes part in this cleavage reaction. Therefore, we suggest that the processing of the precursor-10Sb RNA to 10Sb RNA is carried out by a thus-far unidentified endoribonuclease. The accumulation of a RNA molecule in a RNase E- mutant that does not contain a cleavage site for RNase E has been encountered previously and can be explained by assuming the existence of a RNA processing complex in the E. coli cell.
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PMID:Identification of a precursor molecular for the RNA moiety of the processing enzyme RNase P. 619 33

Strains of Escherichia coli having a thermosensitive RNase E produce a number of 5-S ribosomal RNA precursors at a non-permissive temperature. One of these precursors, 9-S RNA, was reported earlier [Ghora, B.K. and Apirion, D. (1978) Cell, 15, 1055-1066]. Here we show the existence of additional precursors to 5-S rRNA, originating from a number of rRNA genes. All the precursors are very similar in the first 200 nucleotides and the last part of this sequence contains the mature 5-S rRNA. Precursors that contain only these nucleotides (8-S RNA) accumulate. They probably originate from the rrn genes C, D and F which contain trailer tRNAs. The 9-S RNA precursors contain in addition a termination stem and loop structure and are derived from genes which do not contain trailer tRNA (Singh and Apirion, unpublished results). In addition, a 10-S precursor was identified. It contains distal to the 5-S rRNA a trailer tRNA, tRNAAsp, and a transcription termination signal. It is derived from the rrnF gene. The accumulation of an RNA precursor containing an RNase P site in an rne mutant suggests that the efficiency of one RNA processing enzyme depends on the activity of other RNA processing enzymes.
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PMID:Ribonuclease E is involved in the processing of 5-S rRNA from a number of rRNA transcription units. 674 92

M1 RNA, the catalytic subunit of RNase P from Escherichia coli, is transcribed in vivo as a precursor with extra nucleotides at the 3' end. Although it was suggested previously that RNase E is not responsible for the 3' processing of M1 RNA, we show that RNase E is the enzyme responsible for this reaction. At nonpermissive temperatures, the 3' processing of M1 RNA is abolished in a temperature-sensitive strain of E. coli that harbors a mutation in the gene for RNase E. Enhanced processing of M1 RNA is correlated with the overproduction of RNase E in vivo and processing is also correlated with the activity of this enzyme during the course of its purification. The biosynthesis of mature M1 RNA can proceed from transcripts that are produced under the control of a proximal promoter, as well as from a distal, upstream promoter. Transcription from the distal promoter results in a polycistronic transcript that includes four open reading frames and the transcript of rnpB, the gene coding for M1 RNA. The enzymatic activity that removes the 5' nucleotides from the precursor to M1 RNA is not due to RNase E, RNase P, or RNase III alone.
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PMID:Processing of the precursor to the catalytic RNA subunit of RNase P from Escherichia coli. 748 4

RNA processing in Escherichia coli and some of its phages is reviewed here, with primary emphasis on rRNA and tRNA processing. Three enzymes, RNase III, RNase E and RNase P are responsible for most of the primary endonucleolytic RNA processing events. The first two are proteins, while RNase P is a ribozyme. These three enzymes have unique functions and in their absence, the cleavage events they catalyze are not performed. On the other hand a relatively large number of exonucleases participate in the trimming of the 3' ends of tRNA precursor molecules and they can substitute for each other. Primary processing is the first event that happens to the nascent RNA molecule, while in secondary RNA processing, the substrate is a product of a primary processing event. Although most RNA processing occurs in RNP particles, it seems that only in secondary RNA processing is the RNP particle required for the reaction. Bacteria and especially bacteriophages contain self-splicing introns which in cases were probably acquired from other species.
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PMID:RNA processing in prokaryotic cells. 768 12


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