Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Many human mitochondrial disorders are associated with mutations in tRNA genes or with deletions of regions containing tRNA genes, all of which may be suspected to play a role in recognition by RNase P. Here we describe the analysis of five such mutations. The results presented here demonstrate that none of these mutations result in errors in RNase P function. Further studies of mutations in tRNAs need to be pursued to elucidate the identity elements for RNase P function in mammalian mitochondria.
Mol Biol Rep
PMID:tRNA processing in human mitochondrial disorders. 890 9

Hyperprocessing is defined as a further processing of mature RNA that produces another functional RNA. Hyperprocessing occurs in Drosophila cells. In the transposon copia-related retrovirus-like particles of Drosophila, a 39-nucleotide-long fragment from the 5'region of Drosophila initiator methionine tRNA is used as the primer for copia minus-strand reverse transcription. This primer tRNA fragment is thought to be produced by cleavage within the mature tRNA sequence. We found that the catalytic RNA subunit of RNase P catalyzes this hyperprocessing in vitro and that this cleavage is dependent of the occurrence of an altered conformation of the tRNA substrate. In this review, I will summarize our work from the finding of the functional RNA fragment to the finding of a dynamic tRNA structure.
Mol Biol Rep
PMID:RNase P as hyperprocessing enzyme: a model for formation of a biologically functional tRNA fragment. 890 6

ColE1 DNA replication is initiated by RNA II and inhibited by RNA I. Control of the replication occurs through the interaction between RNA I and RNA II. Therefore, RNases involved in the metabolism of RNA I and RNA II are expected to play a key role in the control of the ColE1 plasmid replication. RNase H, RNase E, RNase III, RNase P, and polynucleotide phosphorylase carry out the many specific reactions of the RNA metabolism.
Mol Biol Rep
PMID:RNases in ColE1 DNA metabolism. 890 10

We have used genetics as a tool to study the importance of an internal loop (P7) of Escherichia coli RNase P RNA (M1 RNA) in cleavage site selection and the binding of a divalent metal ion(s). The preferred cleavage site on a model tRNA precursor substrate shifted as a result of base-substitutions and deletions within this loop, in particular when changes were introduced at positions directly involved in base-pairing with the 3'-terminal RCCA motif of the substrate. Additionally, these changes in M1 RNA resulted in alterations in the binding of a divalent metal ion(s) in the vicinity of this internal loop as revealed by lead(II)-induced cleavage. From these data we conclude that the structural integrity of the P7 loop is important for both cleavage site selection and divalent metal ion binding. Cross-linking experiments using precursors carrying a 4-thioU immediately 5' of two independent cleavage sites suggest that close contact points between M1 RNA and nucleotides at these cleavage sites depend on the interaction between M1 RNA and the 3'-terminal RCCA motif of the substrate. Our findings further support the view that there are at least two different ways for the tRNA domain of a tRNA precursor to interact with M1 RNA. These results support a model in which base-pairing between M1 RNA and its substrate results in a re-coordination of a divalent metal ion(s) such that cleavage at the correct position is accomplished.
J Mol Biol 1996 Nov 15
PMID:Residues in Escherichia coli RNase P RNA important for cleavage site selection and divalent metal ion binding. 894 68

The 5' end of mature tRNAs is formed by the endonucleolytic removal of a leader sequence. RNase P, the enzyme generally responsible for this event, makes use of structural information contained within the tRNA domain of the precursor to recognize substrates and direct cleavage to the tRNA's 5' end. Human mitochondrial tRNA(Ser(AGY)GCU, a tRNA that , a tRNA that shows several structural deviations from "classical" as well as mitochondrial tRNAs, the most prominent of which is the lack of a D domain, is processed at its 5' end via a novel, "non-RNase P" pathway. 5' end maturation of tRNA(Ser(AGY)GCU is the consequence of 3' end processing of the abutting tRNA(His), precisely flanking the tRNA(Ser(AGY)GCU gene at its 5' end. Deletion of this adjoining tRNA structure abolishes efficient 5' end maturation of tRNA(Ser(AGY)GCU in vitro, suggesting that the human mitochondrial tRNA(SeR(AGY)GCU employs a 5'abutting tRNA as a processing signal for 5' end maturation in a kind of molecular commensalism.
J Mol Biol 1997 Jan 31
PMID:Processing of human mitochondrial tRNA(Ser(AGY))GCU: a novel pathway in tRNA biosynthesis. 903 56

Escherichia coli ribonuclease P (RNase P), a ribonucleoprotein complex which primarily functions in tRNA biosynthesis, is composed of a catalytic RNA subunit, M1 RNA, and a protein cofactor, C5 protein. The fluorescence emission spectrum of the single tryptophan residue-containing C5 protein exhibits maxima at 318 nm and 332 nm. Based on a comparison of the emission spectra of wild-type C5 protein and some of its mutant derivatives, we have determined that the 318 nm maximum could be the result of a complex formed in the excited state as a result of hydrophobic interactions between Trp109, Phe18 and Phe73. The analogous tryptophan fluorescence emission spectra of wild-type C5 protein and the barstar mutant W38F/W44F, taken together with the detailed structural information available for barstar, provide a possible explanation for the unusual emission spectrum of C5 protein.
J Mol Biol 1997 Apr 11
PMID:Fluorescence properties of a tryptophan residue in an aromatic core of the protein subunit of ribonuclease P from Escherichia coli. 913 9

The processing of precursor tRNAs and some other small cellular RNAs by M1 RNA, the catalytic subunit of Escherichia coli ribonuclease P, is accelerated by C5 protein (the protein cofactor) both in vitro and in vivo. In an effort to understand the mechanism by which the protein cofactor promotes and stabilizes certain conformations of M1 RNA that are most efficient for RNase P catalysis, we have used site-directed mutagenesis to generate mutant derivatives of C5 protein and assessed their ability to promote RNase P catalysis in vivo and in vitro. Our results indicate that certain conserved hydrophobic and basic residues in C5 protein are important for its function and that single amino acid residue changes in C5 protein can alter the substrate specificity of the RNase P holoenzyme.
J Mol Biol 1997 Apr 11
PMID:Analysis of the functional role of conserved residues in the protein subunit of ribonuclease P from Escherichia coli. 913 14

The Escherichia coli rnpA gene encodes C5 protein, the protein component of RNase P. The rnpA49 mutation renders the C5 protein thermosensitive, which results in thermosensitivity of RNase P function. The chromosomal DNA region from Brevibacterium albidum that complements the rnpA49 mutation was analysed. The gene capable of complementing the growth defect of an rnpA49 mutant strain at nonpermissive temperature was identified as the gene for an arginine tRNA with anticodon CCG by a deletion analysis combined with complementation assays. Transcription of the arginine tRNA gene carried on a multicopy plasmid was correlated with the complementation of the rnpA49 mutation, indicating that the gene product is indeed responsible for complementation of the rnpA49 mutation.
Mol Gen Genet 1997 Apr 28
PMID:The Brevibacterium albidum gene encoding the arginine tRNACCG complements the growth defect of an Escherichia coli strain carrying a thermosensitive mutation in the rnpA gene at the nonpermissive temperature. 918 Jul 1

A complex pseudoknot structure surrounds the first ribosome initiation site in the Escherichia coli alpha mRNA and mediates its regulation by ribosomal protein S4. A 112 nt RNA fragment containing this pseudoknot exists in two conformations that are resolvable by gel electrophoresis below room temperature. Between 30 degrees C and 45 degrees C the conformers reach thermodynamic equilibrium on a time scale ranging from one hour to one minute, and the interconversion between conformers is linked to H+, K+ and Mg2+ concentrations. Mg2+ favors formation of the "fast" electrophoretic form: a single Mg2+ is bound in the rate-limiting step, followed by cooperative binding of approximately 1.7 additional ions. Binding of the latter ions provides most of the favorable free energy for the reaction. However, the "slow" form binds about the same number of Mg ions, albeit more weakly, so that saturating Mg2+ concentrations drive the equilibrium to only approximatley 70% fast form. A single H+ is taken up in the switch to the "slow" conformer, which has apparent pK approximately 5.9; low pH also stabilizes part of the pseudoknot structure melting at approximately 62 degrees C. Mg2+ and H+ appear to direct alpha mRNA folding by relatively small (10 to 100-fold) differences in their affinities for alternative conformers. K+ has very little effect on the conformational equilibrium, but at high concentrations accelerates interconversion between the conformers. The alpha mRNA conformational switch is similar in its slow kinetics, large activation energy, and Mg2+ dependence of the equilibrium constant to slow steps in the folding of tRNA, group I introns, and RNase P RNA tertiary structures, though it differs from these in the association of a single Mg2+ with the rate-limiting step.
J Mol Biol 1997 Jul 18
PMID:Effects of Mg2+, K+, and H+ on an equilibrium between alternative conformations of an RNA pseudoknot. 923 10

We characterized a panel of human RNase MRP/RNase P autoantibodies by immunoprecipitation, immunodepletion, immunoaffinity purification and immunoblotting. We report on the protein spectrum that is recognized by RNase MRP/RNase P autoantibodies. We also describe another, related patient serum that based on these assays does not immunoprecipitate RNase P/MRP/Th40. This autoantibody 'KC', however, coimmunoprecipitates the RNase MRP/RNase P associated RNAs from HeLa and La9 cell extracts as shown by nuclease protection experiments.
Mol Biol Rep 1998 Mar
PMID:Further characterization of human RNase MRP/RNase P and related autoantibodies. 954 70


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