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)

Surface-induced overproduction of flagellin is one of the hallmarks of Proteus mirabilis swarmer cell differentiation. In this study, we analyzed the nucleotide (nt) and amino acid (aa) sequences, and expression of the P. mirabilis flagellin-encoding gene (fliC) region. The nt sequence analysis of a 3567-bp region reveals three ORFs, each with homology to known Escherichia coli flagellar genes. The first ORF corresponds to fliD, the gene encoding the flagellar filament capping protein, FliD (HAP2). The second and third ORFs are highly homologous to each other and to fliC genes from many other Gram- bacteria. To distinguish between the two alleles, we have designated these genes fliC1 and fliC2. Sequences highly homologous to promoter sites for the alternate sigma factor of RNA polymerase, sigma 28, are found 5' to the start of each gene. Additionally, both fliC1 and fliC2 have a conserved direct tandem repeat (DTR) sequence upstream from the sigma 28 promoter that may have functional significance in the transcriptional control of fliC expression during swarmer cell differentiation. Both FliC1 and FliC2 were produced in E. coli, but only FliC1 could complement FliC- mutants of E. coli. Southern hybridization data indicate the presence of fliC1 and fliC2 in six distinct P. mirabilis strains, indicating that multiple flagellin-encoding genes are common in P. mirabilis. Hybridization data also suggest the presence of a third flagellin-encoding gene, fliC3, in all isolates. The possible significance of multiple fliC in swarmer cell differentiation is discussed.
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PMID:Sequence and genetic analysis of multiple flagellin-encoding genes from Proteus mirabilis. 792 35

The Tn5 insertion into the genome of Rhizobium leguminosarum bv viciae VF39, resulting in non-mucoid growth and formation of non-N2-fixing nodule-like structures on Vicia faba plants, was mapped within a 1.4-kb EcoRV-SacI fragment. Nucleotide sequence analysis revealed an ORF (pss4) of 263 amino acids (aa). Three transcription start points (tsp) were determined. Two of them were localized upstream from the first GTG codon; the third tsp was mapped in front of the second putative start codon (GTG) corresponding to Val64 of the Pss4 aa sequence. The expression of pss4 in a T7 RNA polymerase/promoter system produced a single approx. 29-kDa protein. Pss4 reveals similarity to several proteins involved in polysaccharide biosynthesis in various Rhizobium species. A nearly complete homology was found with PssA from Rl biovar phaseoli 8002 [Borthakur et al., Mol. Gen. Genet. 213 (1988) 155-162], except that Pss4 has an additional 63 aa on its N terminus.
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PMID:The pss4 gene from Rhizobium leguminosarum by viciae VF39: cloning, sequence and the possible role in polysaccharide production and nodule formation. 795 35

The mitochondrial DNA of Podospora anserina is complex, consisting of a characteristic set of genes with a large number of introns and a substantial amount of sequence of unknown function and origin. In addition, as indicated by various types of reorganization, this genome is highly flexible. Here we report the identification of three unassigned mitochondrial open reading frames (ORF P', ORF Q', ORF 11) as remnants of a rearranged viral-type RNA polymerase gene. These ORFs are not transcribed and may be derived from the integration of a linear plasmid of the type recently identified in a mutant of P. anserina.
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PMID:Three mitochondrial unassigned open reading frames of Podospora anserina represent remnants of a viral-type RNA polymerase gene. 808 84

The transcriptional elongation factor TFIIS causes stimulation of RNA polymerase II elongation and readthrough of some of the elongation blocks. We present cloning and sequence characterization of the human TFIIS gene and a pseudogene. The intron-less organization of both of these genes indicates that previously identified cDNAs which suggested the presence of an intron were the products of cloning artifacts. The gene is organized in an uninterrupted ORF which codes for 301 amino acids, whereas the pseudogene lacks an ORF able to code for a full-length protein. The potential promoter for the gene has two putative GC-box-type consensus sequences, two CCAAT-box consensus sequences, and is bounded by a human Alu sequence. Two potential transcriptional termination signal sequences downstream from the consensus polyadenylation signal are proposed.
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PMID:Characterization of the gene encoding the human transcriptional elongation factor TFIIS. 811 16

We have sequenced overlapping complementary DNA clones representing the viral double-stranded (ds) RNA from hypovirulent strain NB58 of the chestnut blight fungus Cryphonectria parasitica. Cryphonectria hypovirus 2-NB58 (CHV2-NB58) dsRNA contains 12,507 base pairs, excluding the poly(A) tail at the 3' end of the plus strand, and is organizationally similar to the largest dsRNA from the virus of strain EP713 (CHV1-713; identical to HAV; Shapira et al., (1991), EMBO J. 10, 731-739). CHV2-NB58 and CHV1-713 dsRNAs share approximately 60% nucleotide sequence identity. On the poly(A)-containing strand of CHV2-NB58, a 487-residue nontranslated region precedes two open reading frames, designated ORF A (438 codons) and ORF B (3291 codons). The connecting pentanucleotide sequence UAAUG (1802-1806) terminates ORF A and initiates ORF B. In contrast to the 69-kDa ORF A product of CHV1-713, the 50-kDa CHV2-NB58 ORF A product did not undergo autoproteolysis under the conditions tested, nor were motifs associated with cysteine proteases present in the CHV2-NB58 ORF A sequence. CHV2-NB58 ORF B products appear to be homologous with CHV1-713 ORF B products, and the motifs involved in autoproteolysis of the N-terminal 48 kDa of CHV1-713 ORF B were identified in the CHV2-NB58 ORF B product. Motifs associated with RNA polymerase and helicase activities were highly conserved between CHV2-NB58 and CHV1-713 and were found at similar genomic positions in the C-terminal half of ORF B.
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PMID:A viral dsRNA element of the chestnut blight fungus with a distinct genetic organization. 818 35

The recently characterized fecal-orally transmitted agent of hepatitis E (formerly known as enterically transmitted non-A, non-B hepatitis) has been determined to be a new type of positive strand RNA virus. The complete sequencing of four different geographic isolates of the hepatitis E virus (HEV) has confirmed a similar genetic organization not previously recognized in nonenveloped positive strand RNA viruses. The approximately 7.5 kb RNA genome (including polyA tail) has nonstructural genes located at the 5' end and structural genes at the 3' end. Expression of these viral genes occurs in at least 3 different forward open reading frames. The largest open reading frame begins 27 nucleotides (nt) downstream of the apparent noncoding 5' end and extends 5,079 nt. Multiple nonstructural gene motifs/domains have been recognized in this 5' ORF1 including a methyltransferase, a papain-like protease, a helicase and the RNA-dependent, RNA polymerase. The second major ORF2 begins 37nt downstream of ORF1 and extends 1980 nt before terminating 65 nt upstream of the polyadenylation site. A third ORF of only 369 nt was identified by immunoscreening experiments as encoding an immunogenic epitope of the virus. Expression of the downstream ORF2 may occur through internal subgenomic RNA initiation at a sequence element found to have homology to internal RNA initiation sequences in Sindbis virus. This element in the HEV genome maps near the apparent 5' end of one of two identified subgenomic messages. The genomic organization and expression of HEV will be discussed and a hypothesis presented regarding the viral replication strategy.
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PMID:Molecular organization and replication of hepatitis E virus (HEV). 821 99

From sequence comparisons between the tobramovirus genomes an open reading frame (ORF-X) potentially encoding a small, positively charged protein (33- to 45-amino-acids long) was found to overlap the immediate 3' and 5' sides of the transport protein gene and coat protein gene, respectively. In vitro translation of the monocistronic artificial transcripts generated with T7 RNA polymerase yielded a protein of M(r) 4000 (p4) and an unexpected trypsin-sensitive complex of M(r) 54,000 that was resistant to reduction with 2-mercaptoethanol but could be dissociated by 8 M urea. Assembly of this complex was inhibited completely by site-directed mutagenesis within a conserved, positively charged 5-amino-acid long segment of the ORF-X protein. After centrifugation in low salt buffer the 54-kDa complex remained mostly associated with ribosomes. Apparently this complex represents a specific aggregate of the p4 product of ORF-X with a protein of approximate M(r) 50,000 that is a component of the translation apparatus.
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PMID:A novel open reading frame in tobacco mosaic virus genome coding for a putative small, positively charged protein. 828 38

To analyze the proteins produced from the rubella virus (RUB) nonstructural protein open reading frame (NSP-ORF), a DNA containing the RUB NSP-ORF was introduced into the expression vector pTM3 in which the sequences to be expressed are downstream from a T7 RNA polymerase promoter. In cells infected with a vaccinia virus recombinant which expresses T7 RNA polymerase and transfected with this plasmid, three RUB-specific products with electrophoretic mobilities of 200, 150, and 97 kDa were clearly visible. By computer alignment, the presence of a cysteine protease was predicted within the NSP-ORF (A. E. Gorbalenya et al., FEBS Lett. 288, 201-205, 1991). When the Cys proposed as the catalytic residue of this protease (Cys1151) was mutated to a Gly, only the 200-kDa product was produced, demonstrating that the Cys is important in the activity of the protease responsible for the processing of the RUB NSPs and that the 150- and 97-kDa species are processing products. Transfections with deletion mutants revealed that the 150-kDa processing product is derived from the amino-terminal two-thirds of the ORF and that both the protease and the cleavage site on the COOH-terminal side of the 150-kDa product are between amino acids 1005 and 1507 of the ORF.
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PMID:Expression of the rubella virus nonstructural protein ORF and demonstration of proteolytic processing. 829 Dec 41

pClT5, a linear mitochondrial (mt) plasmid from Claviceps purpurea, strain T5, was sequenced and compared to pClK1, a linear mt plasmid from an unrelated C. purpurea strain. Both plasmids have terminal proteins (TPs) at their inverted terminal repeats (TlR). The TlRs of both plasmids show short conserved sequences, which are probably involved in plasmid transcription and replication. The coding capacity of pClT5 and pClK1 is similar: there are two large ORFs (ORF1 and ORF2) homologous to the DNA and RNA polymerase ORFs of pClK1 and several small hydrophobic ORFs. ORF3 shows homology to a small ORF of the Neurospora crassa mt plasmid maranhar and is transcribed. ORF6 of pClT5 is homologous to ORF4 of pClK1; both are transcribed and are possible candidates for the TP encoding ORF.
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PMID:pClK1 and pClT5--two linear mitochondrial plasmids from unrelated Claviceps purpurea strains: a comparison. 830 35

The Klebsiella aerogenes nac gene, whose product is necessary for nitrogen regulation of a number of operons, was identified and its DNA sequence determined. The nac sequence predicted a protein a 305 amino acids with a strong similarity to members of the LysR family of regulatory proteins, especially OxyR from Escherichia coli. Analysis of proteins expressed in minicells showed that nac is a single-gene operon whose product has an apparent molecular weight of about 32 kDa as measured in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Immediately downstream from nac is a two-gene operon, the first gene of which encodes another member of the LysR family. Upstream from nac is a tRNAAsn gene transcribed divergently from nac. About 60 bp upstream from the nac open reading frame lies a sequence nearly identical to the consensus for sigma 54-dependent promoters, with the conserved GG and GC nucleotides at -26 and -14 relative to the start of transcription. About 130 bp farther upstream (at -153 relative to the start of transcription) is a sequence nearly identical to the transcriptional activator NTRC-responsive enhancer consensus. Another weaker NTRC-binding site is located adjacent to this site (at -133 relative to the start of transcription). Thus, we propose that nac is transcribed by RNA polymerase carrying sigma 54 in response to the nitrogen regulatory (NTR) system. A transposon located between the promoter and the nac ORF prevented NTR-mediated expression of nac, supporting this identification of the promoter sequence. The insertion of over 5 kb of transposon DNA between the enhancer and its target promoter had only a weak effect on enhancer-mediated regulation, suggesting that enhancers may be able to act at a considerable distance on the bacterial chromosome.
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PMID:The nac (nitrogen assimilation control) gene from Klebsiella aerogenes. 845 53


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