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)

Human cells contain a nuclear protein interacting with Alu repeats, and this protein seems to recognize a conserved sequence motif, GGAGGC, present within the RNA polymerase III promoter and within the SV40 T-antigen-dependent ARS-like element. To study the potential functional role of this element, we have inserted the sequence into a chloramphenicolacetyltransferase (CAT) expression vector with a SV40 promoter and enhancer element from the up-stream region of the human c-myc gene, and transfected HeLa cells with the resulting plasmid. Analysis of expression by the CAT assay indicates that the Alu-derived sequence supresses transcription of the CAT gene driven by the c-myc enhancer/SV40 promoter. The Alu-derived sequence also inhibits ARS activity of the c-myc enhancer. The data allow the explanation of the transcriptional inactivity of Alu repeats in HeLa cells, and suggest the existence of a negative control of Alu transcription.
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PMID:Transcription and replication silencer element is present within conserved region of human Alu repeats interacting with nuclear protein. 215 7

The human gastric (H+ + K+)-ATPase gene (15 kilobases) was cloned, and its nucleotide sequence was determined. The gene has 22 exons and codes a protein of 1,035 residues including the initiator methionine (Mr = 114,047). A conserved lysine-rich sequence with inserted glycine residues was found near the amino terminus of the enzyme. The phosphorylation site and pyridoxal 5'-phosphate- and fluorescein isothiocyanate-binding residues found in the rat and pig enzymes are also conserved in the human enzyme. The positions of introns in the human (H+ + K+)-ATPase gene are essentially the same as those in the human (Na+ + K+)-ATPase alpha and alpha III subunits; but the first introns of the two enzymes are difficult to align, and unlike in the (Na+ + K+)-ATPase gene, the sixth exon in the (H+ + K+)-ATPase gene is not separated by an intron. Furthermore, the ninth intron is located two bases upstream of the position for the corresponding intron of the (Na+ + K+)-ATPase alpha III subunit. The similarity in organization of these two ATPase genes and the homology in the primary structures of their proteins (approximately 60%) suggest that these two genes were derived from a common ancestral gene. However, the 5'-flanking regions of the genes for (H+ + K+)-ATPase and the (Na+ + K+)-ATPase alpha (+) subunit show no apparent sequence homology, indicating that their transcriptions are regulated differently. The control region of the fast-twitch sarcoplasmic reticulum Ca2(+)-ATPase gene also showed no sequence homology to that of (H+ + K+)-ATPase. The 5'-flanking region of the (H+ + K+)-ATPase gene contains potential binding sites for RNA polymerase II and various transcriptional regulation factors and several direct and inverted repeat sequences which may be important for specific and controlled expression of the gene in gastric parietal cells. There are two polyadenylation signals in the 3'-flanking region of the (H+ + K+)-ATPase gene, but the sequence of this region shows no homology to those of the corresponding regions of the genes for the (Na+ + K+)-ATPase alpha and alpha III subunits.
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PMID:Human gastric (H+ + K+)-ATPase gene. Similarity to (Na+ + K+)-ATPase genes in exon/intron organization but difference in control region. 216 Sep 52

The Escherichia coli gene encoding protein n' has been isolated and named priA for primosomal protein A. Protein n' is absolutely required for the conversion of single-stranded phi X174 DNA to the duplex replicative form in an in vitro-reconstituted system. The gene maps to 88.7 minutes on the chromosome adjacent to the cytR locus. Soluble protein extracts from cells harboring the priA gene on a multicopy plasmid contained 45-fold more n' replication activity than wild-type extracts. Enhanced overproduction of greater than 1000-fold was achieved by replacing the natural Shine-Dalgarno sequence with that of the phage T7 phi 10 gene and placing this priA under the control of the T7 phage promoter and RNA polymerase. The priA sequence reveals a 732-amino acid open reading frame and a nucleotide-binding consensus site consistent with the size and ATPase activity of the purified protein. The gene for protein n has been named priB and the putative gene for protein n", priC.
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PMID:The priA gene encoding the primosomal replicative n' protein of Escherichia coli. 216 50

Human transcription factor TFIIE, a ubiquitous factor required for transcription initiation by RNA polymerase II, was purified to homogeneity by a combination of conventional and HPLC steps. The purified TFIIE contained equimolar amounts of 57-kDa (TFIIE-alpha) and 34-kDa (TFIIE-beta) polypeptides that were judged to be functional subunits on the basis of their copurification with transcriptional activity and the recovery of activity following renaturation of polypeptides separated by reverse-phase HPLC. TFIIE-alpha had an independent TFIIE activity whereas TFIIE-beta had no activity alone but enhanced the activity of TFIIE-alpha. In conjunction with gel filtration studies, which indicated a molecular mass of approximately 180 kDa for the native protein, these results suggested that TFIIE is a heterotetramer containing two alpha and two beta polypeptides. Functional studies with the purified TFIIE demonstrated that it is a general initiation factor, required for all of the genes tested, but it failed to show any DNA-dependent ATPase activity.
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PMID:Factors involved in specific transcription by mammalian RNA polymerase II: purification and characterization of general transcription factor TFIIE. 225 Dec 58

The estrogen receptor activation factor (E-RAF)-mediated binding of the receptor-estrogen complex to uterine nuclei was found to involve at least two classes of nuclear macromolecules: (1) the DNA, and (2) a proteinacious component. Evidences are presented to show that at least a portion of (2) is represented by the nuclear RNA polymerases. The receptor-estrogen complex associated in vivo with the nuclear RNA polymerases existed in two distinct forms which sedimented at 3.8 S and 4.8 S on sucrose density gradients. Almost 2/3 of the total radioactivity was associated with the 3.8 S species. Saturation kinetics of the two forms showed that while the 4.8 S form displayed characteristics similar to the classical type I nuclear binding site, the features displayed by the 3.8 S form were closely similar to those of the nuclear type II site. The 4.8 S species is a DNA binding form while the 3.8 S form is non-DNA binding. Anti-E-RAF IIA IgG cross-reacted with both the binding components. Goat uterine E-RAF I, IIA and IIB were purified to homogeneity as described earlier. While E-RAF IIA and IIB destabilized the native DNA structure and induced separation of the DNA strands, E-RAF I performed the opposite function. The reactions required the presence of ATP; all three of them displayed DNA-dependent ATPase activity. In an in vitro transcription system which contained purified RNA polymerase B (rat liver enzyme) and goat uterine DNA, E-RAF IIA and IIB enhanced transcription 7-fold over the control while E-RAF I totally suppressed the transcription process, irrespective of whether it was stimulated earlier by the other two E-RAF forms or not. This E-RAF property remained unchanged even after its association with the 4 S receptor-estrogen complex forming 5 S complex.
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PMID:Molecular aspects of estrogen receptor activation factor (E-RAF) function. 252 74

Human retrotransposons, Alu-family DNA repeats (AFRs), have variable nucleotide sequence but conservative short elements, which may have important functions, are also present. In our previous reports we have described human nuclear DNA-binding protein interacting with AFRs and evidence was presented that the protein recognizes sequence motif 5'-GGAGGC-3' which is conserved in the spacer of RNA polymerase III promoter of AFRs and in the SV40 T-antigen-dependent replication origin of AFRs. In this study it was found that double-stranded synthetic oligonucleotides containing indicated conservative sequences of AFRs actually have high-affinity binding site for HeLa nuclear protein. The data suggest that non-infected human cells contain nuclear DNA-binding protein which recognizes the conservative sequence motif of AFRs - GGAGGC.
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PMID:Human nuclear protein interacting with a conservative sequence motif of Alu-family DNA repeats. 254 28

A transcription factor required for synthesis of accurately initiated run-off transcripts by RNA polymerase II has been purified and shown to have an associated DNA-dependent ATPase (dATPase) activity that is strongly stimulated by the TATA region of promoters. This transcription factor, designated delta, was purified more than 3000-fold from extracts of crude rat liver nuclei and has a native molecular mass of approximately 230 kDa. DNA-dependent ATPase (dATPase) and transcription activities copurify when delta is analyzed by hydrophobic interaction and ion-exchange HPLC, arguing that transcription factor delta possesses an ATPase (dATPase) activity. ATPase (dATPase) is specific for adenine nucleotides; ATP and dATP, but not CTP, UTP, or GTP, are hydrolyzed. ATPase (dATPase) is stimulated by both double-stranded and single-stranded DNAs, including pUC18, ssM13, and poly(dT); however, DNA fragments containing the TATA region of either the adenovirus 2 major late or mouse interleukin 3 promoters stimulate ATPase as much as 10-fold more effectively than DNA fragments containing nonpromoter sequences. These data suggest the intriguing possibility that delta plays a critical role in the ATP (dATP)-dependent activation of run-off transcription through a direct interaction with the TATA region of promoters.
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PMID:An RNA polymerase II transcription factor has an associated DNA-dependent ATPase (dATPase) activity strongly stimulated by the TATA region of promoters. 255 40

Erwinia carotovora RNA polymerase consists of the holoenzyme structure sigma 2 beta beta' sigma as found in Escherichia coli and other bacteria. E. carotovora RNA polymerase can synthesize RNA using lambda, T7 of T4 DNA as templates; however, it is two times less active on these templates and is more temperature-sensitive than the E. coli enzyme. The alpha subunit of the E.. carotovora enzyme is lower in molecular mass than its E. coli counterpart. The sigma factors from E. coli and E. carotovora are similar in size and in their ability to stimulate RNA synthesis by core enzyme on DNA templates such as T7 DNA. An additional protein of 115 000 Da molecular mass, termed gamma, is found associated with E. carotovora RNA polymerase. The gamma protein is tightly associated with the polymerase subunits as it is not dissociated by gel filtration in buffer containing 0.5 M NaCl. It can be purified by passing the Agarose 1.5 m enzyme through coupled Bio-Rex 70 and DEAE-cellulose columns. The gamma-protein, when present in excess over the sigma subunit, inhibits holoenzyme activity on T7 DNA but not on poly[d(A-T)]and may thus interfere with sigma activity. The gamma protein by itself cannot transcribe T7 DNA or poly[d(A-T)], nor does it stimulate core enzyme activity on T7 DNA. E. carotovora rho has a subunit molecular mass of 48 000 Da and exhibits RNA-dependent phosphohydrolysis of adenosine ribonucleoside triphosphate. E. coli and E. carotovora rho are indistinguishable immunologically, as total fusion of precipitin bands is observed. E. carotovora rho elutes from a phosphocellulose column at a salt concentration of about 0.21 M KCl, compared to that of 0.29 M KCl for E. coli rho. The poly(C)-dependent ATPase activity of E. carotovora rho is more-temperature sensitive and is six to ten times less active than that of E. coli rho. E. carotovora rho is capable of terminating RNA transcripts, as indicated by a decrease in RNA synthesis using lambda or T7 DNA as template and E. carotovora or E. coli polymerase as the transcribing-enzyme.
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PMID:Purification of RNA polymerase and transcription-termination factor Rho from Erwinia carotovora. 257 93

We have developed an homologous in vitro system from spinach chloroplasts that correctly initiates transcription of the plastid genes for the large subunit of ribulose-1,5-bisphosphate carboxylase (rbcL) and the beta subunit of the plastid ATPase (atpB). The transcriptionally active extracts from spinach chloroplasts require circular DNA templates for specific initiation. The RNA polymerase activity is insensitive to rifampicin. The extent of transcription in vitro is a function of the extract:template ratio. The efficiency of the rbcL transcription in vitro is more than one transcript per one hundred templates per hour.
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PMID:An in vitro system for accurate transcription initiation of chloroplast protein genes. 286 Jun 36

DNA-dependent ATPase IV has been purified to near homogeneity from the Novikoff rat hepatoma. The enzyme is devoid of DNA polymerase, RNA polymerase, exonuclease, endonuclease, phosphomonoesterase, 3'- or 5'-phosphodiesterase, polynucleotide kinase, protein kinase, topoisomerase, helicase or DNA reannealing activities at a detection level of 10(-5) to 10(-7) relative to the ATPase activity. The enzyme is a monomer of Mr 110,000, has a sedimentation coefficient of 5.9 S, a Stokes radius of 40 A and a frictional coefficient of 1.32. In the presence of Mg2+ ion and a polynucleotide effector, ATPase IV hydrolyzes either ATP or dATP to the nucleoside diphosphate plus Pi. Other ribo- or deoxyribonucleoside triphosphates are not substrates. ATPase IV utilizes double-stranded DNA and single-stranded DNA as effector; however, it does not utilize poly(dT). The Km for dsDNA or ssDNA is 2.2 microM (nucleotide). A variety of ATP analogues were found to be competitive inhibitors of ATPase IV.
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PMID:Purification and enzymological characterization of DNA-dependent ATPase IV from the Novikoff hepatoma. 296 5


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