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)

The gene for the RNA subunit of ribonuclease P from the extreme thermophilic eubacterium T. thermophilus HB8 was cloned using oligonucleotide probes complementary to conserved regions of RNase P RNA subunits from proteobacteria. The monocistronic gene and its flanking regions were sequenced. The gene is enclosed by a promoter and a rho-independent terminator. Nuclease S1 protection analyses showed that the primary transcript is identical with the mature RNA, i.e. no processing events are involved. The stem and loop structure of the terminator remains part of the mature molecule. In vitro transcription of the cloned gene with purified RNA polymerase from T. thermophilus yields the same RNA product as in vivo, indicating that no other components except RNA polymerase are involved in the synthesis of the RNA. RNase P RNA from T. thermophilus cleaved a pre-tRNA(Tyr) from E. coli with highest efficiency between 55 degrees C and 65 degrees C. The T. thermophilus RNA, which has a G-C content of 86% in helical regions, displays several structural idiosyncrasies, although its secondary structure is similar to that of proteobacteria. Numerous invariable nucleotides in the structural core of eubacterial RNase P RNAs are also conserved in the RNA from the extreme thermophilic eubacterium.
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PMID:Analysis of the gene encoding the RNA subunit of ribonuclease P from T. thermophilus HB8. 171 85

Phylogenetic-comparative and mutational analyses were used to elucidate the structure of the catalytically active RNA component of eubacterial ribonuclease P (RNase P). In addition to the refinement and extension of known structural elements, the analyses revealed a long-range interaction that results in a second pseudoknot in the RNA. This feature strongly constrains the three-dimensional structure of RNase P RNA near the active site. Some RNase P RNAs lack this structure but contain a unique, possibly compensating, structural domain. This suggests that different RNA structures located at different positions in the sequence may have equivalent architectural functions in RNase P RNA.
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PMID:Long-range structure in ribonuclease P RNA. 171 34

In humans, the H1 RNA, the RNA subunit of RNase P, is synthesized by RNA polymerase III. We have used block replacement mutagenesis to identify the sequences necessary for in vitro transcription of H1 RNA. We find that multiple cis-acting elements located in the H1 RNA 5'-flanking region are necessary for H1 RNA synthesis; no internal sequences are essential. Required cis-acting elements include sequences resembling proximal sequence element, distal sequence element, and TATA motifs. In this respect, the H1 RNA promoter is similar in structure to the promoters of the genes encoding the U6 snRNA, the 7 SK RNA and the MRP RNA. However, our mutational analysis indicates that the H1 promoter is unexpectedly complex, with several additional cis-acting elements spanning nearly 70 base pairs of the H1 RNA gene 5'-flanking sequence.
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PMID:Multiple cis-acting elements are required for RNA polymerase III transcription of the gene encoding H1 RNA, the RNA component of human RNase P. 172 Jul 74

Eubacterial RNase P contains a catalytic RNA that cleaves 5' leader sequences from precursor tRNAs. We review the current understanding of RNase P RNA structure and evolution, from the perspective of phylogenetic comparative analysis.
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PMID:Structure and evolution of ribonuclease P RNA. 172 25

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

Certain fragments of M1 RNA, the catalytic subunit of RNase P from Escherichia coli, either have no enzymatic activity at all or have altered substrate specificity compared with that of the intact catalytic RNA. After simple mixing in vitro, many of these fragments of M1 RNA can reassociate with other fragments to form complexes that have enzymatic activity typical of wild-type M1 RNA. Furthermore, inactive M1 RNA molecules with internal deletions can be complemented in vitro by other inactive derivatives of M1 RNA that have nonoverlapping deletions. Thus, two inactive molecules of M1 RNA can interact to form an active RNA enzyme. Functional attributes can be assigned to various regions of M1 RNA when the reconstitution process is combined with assays for activity with different substrates.
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PMID:Reconstitution of enzymatic activity from fragments of M1 RNA. 174 79

The RNA subunit of Saccharomyces cerevisiae nuclear RNase P is encoded by a single-copy, essential gene, RPR1. The 369-nucleotide mature form of the RNA has an apparent precursor with an 84-nucleotide 5' leader and approximately 33 nucleotides of additional 3' sequence. Analysis of RPR1 transcription in a strain with a temperature-sensitive lesion in RNA polymerase III shows that the gene is transcribed in vivo by RNA polymerase III. Examination of potential promoter regions using both progressive upstream deletions and point mutations indicates that at least two sequences contained within the 5' leader region are essential for expression in vivo, while sequences farther upstream influence efficiency. The required leader elements resemble tRNA gene-like A-box and B-box internal promoters in sequence and spacing. As in the tRNA genes, transcription factor TFIIIC binds to this region in vitro and binding is severely reduced by either A-box or B-box point mutations that impair expression in vivo. It thus appears that the yeast RNase P RNA gene has adopted a promoter strategy that places an RNA polymerase III "internal" promoter upstream of the mature structural domain to help drive transcription.
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PMID:Expression of RNase P RNA in Saccharomyces cerevisiae is controlled by an unusual RNA polymerase III promoter. 187 Nov 14

Precursor tRNAAsp molecules, containing a 26-base 5' leader, were treated with diethylpyrocarbonate, 50% hydrazine or anhydrous hydrazine/3M NaCl and then subjected to processing by RNase P RNAs from Escherichia coli or Bacillus subtilis. Fully processed tRNAs and material not successfully cleaved by the catalytic RNAs were analyzed for their content of chemically altered nucleotides. Several bases were identified as being required intact for optimal activity as substrate as judged by exclusion of chemically modified residues from processed molecules, and simultaneous enhancement in material that was not recognized as substrate. Such nucleotides cluster near the site of cleavage at the mature 5' end and in the T stem and loop. Purines at residues 1 and 2 adjacent to the site of cleavage, position 57 in the T loop, and site 64 in the T stem exhibited the most pronounced effects. These results suggest a model of recognition of substrate by RNase P RNAs in which the ribozyme interacts with the corner of the precursor tRNA's three dimensional structure, where the T- and D-loops are juxtaposed, and extends along the top of the molecule back towards the site of catalysis.
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PMID:Nucleotides in precursor tRNAs that are required intact for catalysis by RNase P RNAs. 190 90

The gene coding for the AU-rich RNA required for mitochondrial RNase P activity in Saccharomyces cerevisiae codes for a 490-base RNA while that in Candida glabrata codes for a 227-base RNA. We have detected a 140-nucleotide RNA coded by the mitochondrial DNA from Saccharomycopsis fibuligera by hybridization with an oligonucleotide complementary to a conserved sequence found in mitochondrial and prokaryotic RNase P RNAs. DNA sequence analysis of the mitochondrial DNA from the region coding for this RNA revealed a second conserved sequence block characteristic of RNase P RNA genes and the presence of a downstream tRNA(Pro) gene. Like previously characterized mitochondrial RNase P RNAs, this small RNA is extremely AU-rich. The discovery of this 140-base RNA suggests that naturally occurring RNase P RNAs may be quite small.
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PMID:Dramatic size variation of yeast mitochondrial RNAs suggests that RNase P RNAs can be quite small. 191 32

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


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