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)

Mammalian MRP (for mitochondrial RNA processing) RNA, also known as 7-2 RNA, is a nuclear encoded small RNA which has been reported to function in two different cellular compartments: in the mitochondria and in the nucleus. The ribonucleoprotein particle which contains the 7-2/MRP RNA, called RNase MRP, has ribonucleolytic activity and shares some structural similarity with RNase P. It has been proposed that in mitochondria, the RNase MRP is responsible for endonucleolytic cleavage of primer RNA during DNA replication. We have characterized the gene and cDNAs encoding 7-2/MRP-like RNA in Arabidopsis and tobacco, and found that in plants this RNA is enriched in nucleoli but is undetectable in purified mitochondria isolated from tobacco leaves or cells grown in suspension. In glycerol gradients tobacco 7-2/MRP RNA cosediments with large approximately 80S structures possibly representing ribosomal precursors. Fractionation of HeLa cells has also revealed that 7-2/MRP resides in the nucleolus and that most of it is associated with complexes sedimenting at approximately 80S, similar to those containing the U3 nucleolar RNA which is known to participate in pre-rRNA processing. These results indicate that the 7-2/MRP ribonucleoparticle may be involved in ribosome biogenesis, in both plant and mammalian cells.
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PMID:7-2/MRP RNAs in plant and mammalian cells: association with higher order structures in the nucleolus. 138 78

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

Sera from patients with autoimmune diseases often contain antibodies that bind ribonucleoproteins (RNPs). Sera from 30 such patients were found to immunoprecipitate ribonuclease P (RNase P), an RNP enzyme required to process the 5' termini of transfer RNA transcripts in nuclei and mitochondria of eukaryotic cells. All 30 sera also immunoprecipitated the nucleolar Th RNP, indicating that the two RNPs are structurally related. Nucleotide sequence analysis of the Th RNP revealed it was identical to the RNA component of the mitochondrial RNA processing enzyme known as RNase MRP. Antibodies that immunoprecipitated the Th RNP selectively depleted murine and human cell extracts of RNase MRP activity, indicating that the Th and RNase MRP RNPs are identical. Since RNase P and RNase MRP are not associated with each other during biochemical purification, we suggest that these two RNA processing enzymes share a common autoantigenic polypeptide.
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PMID:The RNA processing enzyme RNase MRP is identical to the Th RNP and related to RNase P. 247 49

We have investigated the subcellular organization of the four human Y RNAs. These RNAs, which are transcribed by RNA polymerase III, are usually found complexed with the Ro autoantigen, a 60-kD protein. We designed 2'-OMe oligoribonucleotides that were complementary to accessible single-stranded regions of Y RNAs within Ro RNPs and used them in fluorescence in situ hybridization. Although all four Y RNAs were primarily cytoplasmic, oligonucleotides directed against three of the RNAs hybridized to discrete structures near the nucleolar rim. We have termed these structures "perinucleolar compartments" (PNCs). Double labeling experiments with appropriate antisera revealed that PNCs are distinct from coiled bodies and fibrillar centers. Co-hybridization with a genomic DNA clone spanning the human Y1 and Y3 genes showed that PNCs are not stably associated with the transcription site for these Y RNAs. Although 5S rDNA was often located near the nucleolar periphery, PNCs are not associated with 5S gene loci. Two additional pol III transcripts, the RNA components of RNase P and RNase MRP, did colocalize within PNCs. Most interestingly, the polypyrimidine tract-binding protein hnRNP I/PTB was also concentrated in this compartment. Possible roles for this novel nuclear subdomain in macromolecular assembly and/or nucleocytoplasmic shuttling of these five pol III transcripts, along with hnRNP I/PTB, are discussed.
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PMID:A perinucleolar compartment contains several RNA polymerase III transcripts as well as the polypyrimidine tract-binding protein, hnRNP I. 753 9

RNase MRP is a ribonucleoprotein endoribonuclease that has been shown to cleave mitochondrial primer RNA sequences from a variety of sources. The bulk of RNase MRP activity is found in the nucleus where its function remains unknown. Two different approaches have resulted in predictions of distinct secondary structures for RNase MRP RNA. In order to analyze more definitively the higher-order structure of RNase MRP RNA, we have conducted a phylogenetic comparison of the available RNase MRP RNA sequences from human, mouse, rat, cow, toad, and yeast. The resulting secondary structure shares features in common with previously described structures for prokaryotic and eukaryotic RNase P RNAs (1) and RNase MRP RNAs (2, 3). In addition, the phylogenetic structure is consistent with available chemical modification data on RNase MRP RNA and with the detailed analysis of the To antigen binding domain located near the 5' end of the RNase MRP RNA. The structure is not limited to RNase MRP RNAs, but can be expanded to cover both eukaryotic RNase P RNAs and RNase P/MRP RNAs from plants.
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PMID:Secondary structure of RNase MRP RNA as predicted by phylogenetic comparison. 767 63

RNase P and RNase MRP are related ribonucleoproteins. RNase MRP processes mitochondrial precursor- (primer) RNAs, whereas RNase P cleaves precursor-tRNAs to produce their mature 5'-ends. Both RNase P and RNase MRP are associated with the Th/To ribonucleoprotein suggesting possible interrelated pathways and/or functions. All known RNase P and RNase MRP RNAs contain conserved structural elements possibly involved in catalysis/substrate binding, but these elements do not predict all cellular functions of the RNPs.
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PMID:RNase MRP/RNase P: a structure-function relation conserved in evolution? 768 Oct 14

RNase MRP is a site-specific ribonucleoprotein endoribonuclease that processes RNA from the mammalian mitochondrial displacement loop containing region. RNase P is a site-specific ribonucleoprotein endoribonuclease that processes pre-tRNAs to generate their mature 5'-ends. A similar structure for the RNase P and RNase MRP RNAs and a common cleavage mechanism for RNase MRP and RNase P enzymes have been proposed. Experiments with protein synthesis antibiotics have shown that both RNase MRP and RNase P are inhibited by puromycin. We also show that E. coli RNase P cleaves the RNase MRP substrate, mouse mitochondrial primer RNA, exactly at a site that is cleaved by RNase MRP.
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PMID:RNase MRP and RNase P share a common substrate. 768 15

The ribonucleoprotein particle RNase MRP is required for the processing of yeast pre-ribosomal RNA (pre-rRNA). A structurally related particle, RNase P, is universally required for processing of pre-tRNA, but in bacteria and archaea also cleaves a site in the pre-rRNA. This suggests that RNase MRP may have arisen in eukaryotes as a form of RNase P specialized for pre-rRNA processing. Other eukaryotic small nucleolar RNAs may have arisen as trans-acting factors that functionally replace cis-acting pre-rRNA interactions in bacteria and archaea.
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PMID:Birth of the snoRNPs: the evolution of RNase MRP and the eukaryotic pre-rRNA-processing system. 754 38

Two forms of the yeast 5.8S rRNA are generated from a large precursor by distinct processing pathways. Cleavage at site A3 is required for synthesis of the major, short form, designated 5.8S(S), but not for synthesis of the long form, 5.8S(L). To identify components required for A3 cleavage, a bank of temperature-sensitive lethal mutants was screened for those with a reduced ratio of 5.8S(S):5.8S(L). The pop1-1 mutation (for processing of precursor RNAs) shows this phenotype and also inhibits A3 cleavage. The pre-rRNA processing defect of pop1-1 strains is similar to that reported for mutations in the RNA component of RNase MRP; we show that a mutation in the RNase MRP RNA also inhibits cleavage at site A3. This is the first site shown to require RNase MRP for cleavage in vivo. The pop1-1 mutation also leads to a block in the processing of pre-tRNA that is identical to that reported for mutations in the RNA component of RNase P. The RNA components of both RNase MRP and RNase P are underaccumulated in pop1-1 strains at the nonpermissive temperature, and immunoprecipitation demonstrates that POP1p is a component of both ribonucleoproteins. The POP1 gene encodes a protein with a predicted molecular mass of 100.5 kD and is essential for viability. POP1p is the first protein component of the nuclear RNase P or RNase MRP for which the gene has been cloned.
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PMID:The POP1 gene encodes a protein component common to the RNase MRP and RNase P ribonucleoproteins. 792 42

RNase MRP is a ribonucleoprotein endoribonuclease that has been shown to cleave mitochondrial primer RNA sequences from a variety of sources. Most of the RNase MRP activity is found in the nucleus where it plays a role in the processing of 5.8S rRNA. A temperature-conditional point mutation in the yeast RNA component of the enzyme has been identified. This mutation results in a loss of normal rRNA processing at the nonpermissive temperature while cellular levels of the RNA component of RNase MRP remain stable. High-copy suppressor analysis of this point mutation was employed to identify interacting proteins. A unique suppressor, termed SNM1 (suppressor of nuclear mitochondrial endoribonuclease 1), was identified repeatedly. The SNM1 gene was localized to the right arm of chromosome IV, directly adjacent to the SNF1 gene, and it contains an open reading frame encoding a protein of 198 amino acids. The protein contains a leucine zipper motif, a zinc-cluster motif, and a serine/lysine-rich tail. The gene was found to be essential for viability in a yeast cell, consistent with it being a protein component of the RNase MRP ribonucleoprotein complex. Recombinant SNM1 protein binds RNA in both gel retardation and Northwestern assays. Antibodies raised against bacterially expressed proteins identified four separate species in yeast whole cell extracts. Antibodies directed against the SNM1 protein immunoprecipitated RNase MRP RNA from whole-cell extracts without precipitating the structurally and functionally related RNase P RNA. We propose that the SNM1 protein is an essential and specific component of the RNase MRP ribonucleoprotein complex, the first unique protein of this complex to be identified.
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PMID:Characterization of a unique protein component of yeast RNase MRP: an RNA-binding protein with a zinc-cluster domain. 795 20


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