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:2.7.7.6 (RNA polymerase)
34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

S-Adenosyl-L-methionine decarboxylase (AdoMetDC; EC 4.1.1.50) is one of the key regulatory enzymes in the biosynthesis of polyamines. Isolation of genomic and cDNA sequences from rice and Arabidopsis had indicated that this enzyme is encoded by a small multigene family in monocot and dicot plants. Analysis of rice, maize and Arabidopsis AdoMetDC cDNA species revealed that the monocot enzyme possesses an extended C-terminus relative to dicot and human enzymes. Interestingly, we discovered that all expressed plant AdoMetDC mRNA 5' leader sequences contain a highly conserved pair of overlapping upstream open reading frames (uORFs) that overlap by one base. The 5' tiny uORF consists of two or three codons and the 3' small uORF encodes 50-54 residues. Sequences of the small uORFs are highly conserved between monocot, dicot and gymnosperm AdoMetDC mRNA species and the C-terminus of the plant small uORFs is conserved with the C-terminus of nematode AdoMetDC uORFs; such a conserved arrangement is strongly suggestive of a translational regulatory mechanism. No introns were found in the main AdoMetDC proenzyme ORF from any of the plant genes encoding AdoMetDC, whereas introns were found in conserved positions flanking the overlapping uORFs. The absence of the furthest 3' intron from the Arabidopsis gene encoding AdoMetDC2 suggests that this intron was lost recently. Reverse-transcriptase-mediated PCR analysis of the two Arabidopsis genes for AdoMetDC indicated that AdoMetDC1 is abundant and ubiquitous, whereas the gene for AdoMetDC2 is expressed preferentially in leaves and inflorescences. Investigation of recently released Arabidopsis genome sequences has revealed that in addition to the two genes encoding AdoMetDC isolated as part of the present work, four additional genes are present in Arabidopsis but they are probably not expressed.
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PMID:Characterization of monocot and dicot plant S-adenosyl-l-methionine decarboxylase gene families including identification in the mRNA of a highly conserved pair of upstream overlapping open reading frames. 1113 6

Frankia are Gram-positive, filamentous bacteria capable of fixing atmospheric dinitrogen either in the free-living state or in symbiosis with a variety of woody plants. Only a few Frankia genes have been sequenced and gene expression is not well characterized. To isolate a segment of Frankia DNA that functions as an RNA polymerase promoter, fragments of Frankia strain ArI5 genomic DNA were cloned upstream of a promoterless, Vibrio harveyi luxAB cassette. Constructs were screened for luminescence in E. coli and positive clones assayed for in vitro transcription activity with a partially purified Frankia RNA polymerase extract. Primer extension analysis of in vitro transcripts produced from one clone, GLO7, identified two major transcription start sites, TSP-1 and TSP-2, 52 bp apart. Deletion analysis then localized sequences essential for promoter activity. The upstream promoter region, GLO7p1, contains sequences resembling the -35 element of a Streptomyces promoter and the -35 and -10 elements of the canonical E. coli promoter. Also within this region are two pentamers identical to sequences near the 5' end of the Frankia strain CpI1 glutamine synthetase gene. The second promoter, GLO7p2, contains a putative NtrC binding site at -145 and a possible sigma(N)-RNA polymerase recognition sequence at -14 suggesting that GLO7p2 may be a nitrogen-regulated promoter. An in vivo transcript representing an ORF of 498 aa starting 64 bp downstream of the distal transcription start, TSP-1, was detected by RT-PCR. This supports the conclusion that this DNA fragment has promoter activity in vivo as well as in vitro.
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PMID:Frankia sequences exhibiting RNA polymerase promoter activity. 1115 67

We characterized the consensus sequence and structure of a long terminal repeat (LTR) retrotransposon from the genome of the human blood fluke, Schistosoma japonicum, and have named this element, Gulliver. The full length, consensus Gulliver LTR retrotransposon was 4788 bp, and it was flanked at its 5'- and 3'-ends by LTRs of 259 bp. Each LTR included RNA polymerase II promoter sequences, a CAAT signal and a TATA box. Gulliver exhibited features characteristic of a functional LTR retrotransposon including two read through (termination) ORFs encoding retroviral gag and pol proteins of 312 and 1071 amino acid residues, respectively. The gag ORF encoded motifs conserved in nucleic acid binding proteins, while the pol ORF encoded conserved domains of aspartic protease, reverse transcriptase (RT), RNaseH and integrase, in that order, a pol pattern conserved in the gypsy lineage of LTR retrotransposons. Whereas the sequence and structure of Gulliver was similar to that of gypsy, phylogenetic analysis revealed that Gulliver did not group particularly closely with the gypsy family. Rather, its closest relatives were a LTR retrotransposon from Caenorhabditis elegans, mag from Bombyx mori and, to a lesser extent, easel from the salmon Oncorhynchus keta. Dot blot hybridizations indicated that Gulliver was present at between 100 and several thousand copies in the S. japonicum genome, and Southern hybridization analysis suggested its probable presence in the genome of Schistosoma mansoni. Transcripts encoding the RT domain of Gulliver were detected by RT-PCR in larval and adult stages of S. japonicum, indicating that (at least) the RT domain of Gulliver is transcribed. This is the first report of the sequence and structure of an LTR retrotransposon from any schistosome or indeed from any species belonging to the phylum Platyhelminthes.
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PMID:Gulliver, a long terminal repeat retrotransposon from the genome of the oriental blood fluke Schistosoma japonicum. 1124 79

Ralstonia metallidurans CH34 can use biphenyl as carbon and energy source when provided with the catabolic transposon Tn4371. Previous results suggested that this property was dependent on the RNA polymerase subunit sigma(54). The authors sequenced the CH34 rpoN gene and flanking DNA and isolated a CH34 rpoN-deficient strain. Analysis of the sequence revealed a set of features conserved in all rpoN genes and flanking DNA regions previously analysed in other bacterial species. Nevertheless, despite this conservation, CH34 differed even from the closely related strain R. eutropha H16 by one particular ORF. The rpoN null mutation did not affect expression of the Tn4371 bph operon although it did alter the ability of the Tn4371 host strain to grow on biphenyl. The CH34 rpoN mutant had lost the capacity for autotrophic growth and for responding to poor nitrogen sources by a decrease in urease and proline oxidase activity. CH34 RNA polymerase sigma(54) thus positively controls autotrophy as well as nitrogen metabolism but only indirectly affects Tn4371-directed biphenyl utilization.
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PMID:Ralstonia metallidurans CH34 RpoN sigma factor and the control of nitrogen metabolism and biphenyl utilization. 1142 71

The genome of brome mosaic virus (BMV), a positive-strand RNA virus in the alphavirus-like superfamily, consists of three capped, messenger-sense RNAs. RNA1 and RNA2 encode viral replication proteins 1a and 2a, respectively. RNA3 encodes the 3a movement protein and the coat protein, which are essential for systemic infection in plants but dispensable for RNA3 replication in plants and yeast. A subset of the 250-base intergenic region (IGR), the replication enhancer (RE), contains all cis-acting signals necessary for a crucial, early template selection step, the 1a-dependent recruitment of RNA3 into replication. One of these signals is a motif matching the conserved box B sequence of RNA polymerase III transcripts. Using chemical modification with CMCT, kethoxal, DMS, DEPC, and lead, we probed the structure of the IGR in short, defined transcripts and in full-length RNA3 in vitro, in yeast extracts, and in whole yeast cells. Our results reveal a stable, unbranched secondary structure that is not dependent on the surrounding ORF sequences or on host factors within the cell. Functional 5' and 3' deletions that defined the minimal RE in earlier deletion studies map to the end of a common helical segment. The box B motif is presented as a hairpin loop of 7 nt closed by G:C base pairs in perfect analogy to the TpsiC-stem loop in tRNA(Asp). An adjacent U-rich internal loop, a short helix, and another pyrimidine-rich loop were significantly protected from base modifications. This same arrangement is conserved between BMV and cucumoviruses CMV, TAV, and PSV. In the BMV box B loop sequence, uridines corresponding to tRNA positions T54 and psi55 were found to be modified in yeast and plants to 5mU and pseudouridine. Together with the aminoacylated viral 3'-end, this is thus the second RNA replication signal within BMV where the virus has evolved a tRNA structural mimicry to a degree that renders it a substrate for classical tRNA modification reactions in vivo.
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PMID:The brome mosaic virus RNA3 intergenic replication enhancer folds to mimic a tRNA TpsiC-stem loop and is modified in vivo. 1172 Feb 93

"Sapporo-like viruses" (SLVs) and "Norwalk-like viruses" (NLVs) are an important cause of acute gastroenteritis in humans. While NLVs have been genetically classified into three major genetic groups consisting of 17 genetic subgroups, a classification of SLVs into comparable genetic groups remains to be determined. In an attempt to classify both SLVs and NLVs uniformly, the sequences of 2 SLV strains newly detected from French infants were analysed together with the published sequences of 9 SLV and 19 NLV strains. Distance and phylogenetic analyses were conducted on the sequences of the capsid gene, RNA polymerase gene, 3' open reading frame (3'ORF), ORF overlapping the capsid gene, and 3' untranslated region (3'UTR). The histogram showing frequency distribution of pairwise distances and the topology of the phylogenetic tree demonstrated that SLVs and NLVs could be classified uniformly on the basis of the entire capsid sequences and that the 11 SLV strains could be genetically classified into 3 major genetic groups, genogroups I, II and III, comprised of 5 genetic subgroups. The differentiation of the 11 SLV strains into these genetic groups was also maintained in the 4 remaining genome regions, while the sequences at the junction between the RNA polymerase and capsid genes were shown to be genogroup-specific.
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PMID:Genetic classification of "Sapporo-like viruses". 1176 15

The two group I introns Nae.L1926 and Nmo.L2563, found at two different sites in nuclear LSU rRNA genes of Naegleria amoebo-flagellates, have been characterized in vitro. Their structural organization is related to that of the mobile Physarum intron Ppo.L1925 (PpLSU3) with ORFs extending the L1-loop of a typical group IC1 ribozyme. Nae.L1926, Nmo.L2563 and Ppo.L1925 RNAs all self-splice in vitro, generating ligated exons and full-length intron circles as well as internal processed excised intron RNAs. Formation of full-length intron circles is found to be a general feature in RNA processing of ORF-containing nuclear group I introns. Both Naegleria LSU rDNA introns contain a conserved polyadenylation signal at exactly the same position in the 3' end of the ORFs close to the internal processing sites, indicating an RNA polymerase II-like expression pathway of intron proteins in vivo. The intron proteins I-NaeI and I-NmoI encoded by Nae.L1926 and Nmo.L2563, respectively, correspond to His-Cys homing endonucleases of 148 and 175 amino acids. I-NaeI contains an additional sequence motif homologous to the unusual DNA binding motif of three antiparallel beta sheets found in the I-PpoI endonuclease, the product of the Ppo.L1925 intron ORF.
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PMID:Characterization of the self-splicing products of two complex Naegleria LSU rDNA group I introns containing homing endonuclease genes. 1189 34

The complete genome of spring viremia of carp virus (SVCV) was cloned and the sequence of 11019 nucleotides was determined. It contains five open reading frames (ORF's) encoding for the nucleoprotein N; phosphoprotein P; matrix protein M; glycoprotein G; and the viral RNA dependent RNA polymerase L. Genes are organised in the order typical for rhabdoviruses: 3'-N-P-M-G-L-5'. The short leader and trailer regions of SVCV exhibit inverse complementarity and are similar to the respective 3' and 5' ends of the genome of vesicular stomatitis virus. To verify the predicted open reading frames proteins were expressed in bacteria and analysed with a polyclonal anti-SVCV serum. Furthermore, monospecific antisera against the distinct viral proteins were generated. Comparison of genome and protein confirm the assignment of SVCV to the genus Vesiculovirus.
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PMID:Determination of the complete genomic sequence and analysis of the gene products of the virus of Spring Viremia of Carp, a fish rhabdovirus. 1190 Aug 42

Posttranscriptional processing of mRNA is an integral component of the gene expression program. By using DNA microarrays, we precisely measured the decay of each yeast mRNA, after thermal inactivation of a temperature-sensitive RNA polymerase II. The half-lives varied widely, ranging from approximately 3 min to more than 90 min. We found no simple correlation between mRNA half-lives and ORF size, codon bias, ribosome density, or abundance. However, the decay rates of mRNAs encoding groups of proteins that act together in stoichiometric complexes were generally closely matched, and other evidence pointed to a more general relationship between physiological function and mRNA turnover rates. The results provide strong evidence that precise control of the decay of each mRNA is a fundamental feature of the gene expression program in yeast.
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PMID:Precision and functional specificity in mRNA decay. 1197 65

The BamHI-J fragment located at 25.8--9.9 map units of the Spodoptera litura multicapsid nucleopolyhedrovirus (SpltMNPV) genome was sequenced. The fragment contained four ORFs, one partial ORF potentially encoding C-terminal of chitinase gene and one partial homologous region (hr). The four ORFs included lef-8 gene, J domain protein gene (bjdp gene), ORF570 and ORF165. The ORF570 revealed 31% identity to the helicase-2 of Lymantria dispar MNPV. The ORF165 was unique to the SpltMNPV. The bjdp gene, reported here for the first time in baculoviruses, was one of J domain family protein genes, and the predicated amino acid sequence possessed a characteristic of J domain protein of other DnaJ proteins at its N-terminus. The lef-8 showed high identities to the homologs of reported baculovirus genomes. As a component of virus-encoded RNA polymerase, the LEF-8 of SpltMNPV had the conserved motif GIKICGIHGQKG near the C-terminal end. Analysis of the LEF-8 phylogenic tree demonstrated SpltMNPV was very closely related to SpliMNPV.
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PMID:Sequence Analysis of the Bam HI-J Fragment of the Spodoptera litura Multicapsid Nucleopolyhedrovirus. 1203 51


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