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)

Transcription factor beta gamma (RAP30/74) from rat liver was previously shown in biochemical studies to control the binding of RNA polymerase II to promoters by a mechanism analogous to that utilized by bacterial sigma factors, by decreasing the affinity of polymerase for nonpromoter sites on DNA and by increasing the affinity of the enzyme for the preinitiation complex (Conaway, R. C., Garrett, K. P., Hanley, J. P., and Conaway, J. W. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 6205-6209). By constructing and analyzing mutants of beta gamma, we have identified a novel functional domain located in the carboxyl terminus of the gamma (RAP30) subunit. This domain shares sequence similarity with region 4 of bacterial sigma factors; in particular, it exhibits striking similarity to the carboxyl-terminal regions 4.1 and 4.2 of SpoIIIC (Bacillus subtilis sigma k). Evidence from biochemical studies argues that a mutant gamma (RAP30), lacking amino acid sequences similar to sigma homology region 4.2, is able to assemble with the beta (RAP74) subunit to form a mutant beta gamma (RAP30/74) with impaired ability to interact with RNA polymerase II.
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PMID:The carboxyl terminus of RAP30 is similar in sequence to region 4 of bacterial sigma factors and is required for function. 142 31

Vaccinia virus encodes a multisubunit DNA-dependent RNA polymerase (EC 2.7.7.6) that is packaged in the infectious virus particle. This polymerase was found to contain a submolar polypeptide of approximately 85 kDa in addition to the core subunits, which consist of two larger and several smaller polypeptides. The polymerase containing the 85-kDa polypeptide was separated from the core polymerase by column chromatography. Although the core polymerase actively transcribed heterologous single-stranded DNA, only the form with the associated 85-kDa polypeptide could act in conjunction with an early stage-specific factor to transcribe double-stranded DNA containing a vaccinia virus early promoter. Peptide sequencing established that the RNA polymerase-associated 85-kDa protein was derived from the vaccinia virus H4L open reading frame, which encodes a 94-kDa polypeptide that we named RAP94. RAP94 is not closely related to prokaryotic sigma 70 or eukaryotic RAP30 RNA polymerase-binding proteins, although there are short regions of sequence similarity. The specific association of RAP94 with viral RNA polymerase was corroborated with antibody raised to a recombinant fusion protein. Unlike the previously defined subunits of vaccinia virus RNA polymerase, RAP94 is synthesized exclusively late in infection, and synthesis could be prevented by a DNA replication inhibitor. The role of RAP94 in mediating specific transcription was demonstrated by using an extract from cells in which the H4L open reading frame had been transiently expressed.
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PMID:RNA polymerase-associated transcription specificity factor encoded by vaccinia virus. 156 50

Initiation of transcription by RNA polymerase II is a complex, multistep process which requires several accessory factors in addition to the polymerase itself. A critical event in transcription initiation is the specific association of RNA polymerase II with promoter DNA. In this report we show that three eukaryotic polypeptides, produced in Escherichia coli and purified to near homogeneity, constitute a minimal set of general transcription factors both necessary and sufficient for specific and stable promoter binding by RNA polymerase II. These polypeptides are the yeast TATA box binding protein TBP, the human general initiation factor TFIIB, and human RAP30, the small subunit of RAP30/74 (or transcription factor IIF). Formation of the polymerase-containing complex required only the TATA box, and not the initiator element (Inr), of the adenovirus major late promoter which was used in these experiments.
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PMID:Recombinant TBP, transcription factor IIB, and RAP30 are sufficient for promoter recognition by mammalian RNA polymerase II. 157 90

RAP30/74 is a heteromeric general transcription initiation factor that binds to mammalian RNA polymerase II. The RAP30 subunit contains a region that is similar in amino acid sequence to the RNA polymerase-binding domain of the Escherichia coli transcription initiation factor sigma 70 (sigma 70). Mammalian RNA polymerase II specifically protected a serine residue in the sigma 70-related region of RAP30 from phosphorylation in vitro. In addition, human RAP30/74 bound to Escherichia coli RNA polymerase and was displaced by sigma 70. These results suggest that RAP30 and sigma 70 have functionally related RNA polymerase-binding regions.
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PMID:Related RNA polymerase-binding regions in human RAP30/74 and Escherichia coli sigma 70. 165 56

RAP30/74 is a human general transcription factor that binds to RNA polymerase II and is required for initiation of transcription in vitro regardless of whether the promoter has a recognizable TATA box (Z. F. Burton, M. Killeen, M. Sopta, L. G. Ortolan, and J. F. Greenblatt, Mol. Cell. Biol. 8:1602-1613, 1988). Part of the amino acid sequence of RAP30, the small subunit of RAP30/74, has limited homology with part of Escherichia coli sigma 70 (M. Sopta, Z. F. Burton, and J. Greenblatt, Nature (London) 341:410-414, 1989). To determine which sigmalike activities of RAP30/74 could be attributed to RAP30, we purified human RAP30 and a RAP30-glutathione-S-transferase fusion protein that had been produced in E. coli. Bacterially produced RAP30 bound to RNA polymerase II in the absence of RAP74. Both partially purified natural RAP30/74 and recombinant RAP30 prevented RNA polymerase II from binding nonspecifically to DNA. In addition, nonspecific transcription by RNA polymerase II was greatly inhibited by RAP30-glutathione-S-transferase. DNA-bound RNA polymerase II could be removed from DNA by partially purified RAP30/74 but not by bacterially expressed RAP30. Thus, the ability of RAP30/74 to recruit RNA polymerase II to a promoter-bound preinitiation complex may be an indirect consequence of its ability to suppress nonspecific binding of RNA polymerase II to DNA.
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PMID:The general transcription factor RAP30 binds to RNA polymerase II and prevents it from binding nonspecifically to DNA. 172 6

At least six chromatographically resolvable general transcription factors may participate in accurate initiation by RNA polymerase II in HeLa cell-derived systems. TFIIF (also termed FC, RAP30/74 and beta/gamma) can bind directly to RNA polymerase II in solution and decrease the affinity of RNA polymerase II for nonspecific DNA. From studies on the kinetics of transcription initiation, on the composition of transcription initiation complexes fractionated by acrylamide gel electrophoresis, and on template competition experiments, TFIIF is known to act at an intermediate stage in initiation complex formation. It acts after TFIID firmly associates with DNA, but coincidentally with or immediately after RNA polymerase II binding to DNA, and before the recruitment of factor TFIIE. TFIIF may or may not have DNA helicase activity. The small subunit (RAP30) of TFIIF has been cloned and shows some amino-acid sequence homology to bacterial sigma factors. We have partially sequenced the RAP74 protein from purified HeLa cells, cloned its complementary DNA and shown that its translation product can interact with RAP30 in vitro as well as in vivo. The cDNA predicts an amino-acid sequence that lacks obvious DNA or RNA helicase motifs. It has regions rich in charged amino acids, including segments containing a higher content of acidic amino acids than are found in strong transcriptional activators such as VP16.
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PMID:Characterization of cDNA for the large subunit of the transcription initiation factor TFIIF. 173 83

RAP30/74 (also known as TFIIF, beta gamma and FC is one of several general factors required for initiation by RNA polymerase II. The small RAP30 subunit of RAP30/74 binds directly to polymerase and appears structurally and functionally homologous to bacterial sigma factors in their RNA polymerase-binding region. RAP30/74 or recombinant RAP30 suppresses nonspecific binding of RNA polymerase II to DNA and is required for RNA polymerase II to assemble stably into a preinitiation complex containing promoter DNA and the general factors TFIID, TFIIA and TFIIB; both RAP30 and RAP74 are physical components of the preinitiation complex. A complementary DNA encoding human RAP30 has been isolated, and here we report the isolation of a cDNA encoding human RAP74. RAP30 and RAP74 produced in Escherichia coli can be used in place of natural human RAP30/74 to direct accurate transcription initiation by RNA polymerase II in vitro.
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PMID:A cDNA encoding RAP74, a general initiation factor for transcription by RNA polymerase II. 173 84

We have purified from whole cell extracts of Saccharomyces cerevisiae a protein which alters the elongation properties of yeast RNA polymerase II in vitro. The yeast elongation stimulatory activity, YES, correlates with a 116-kDa protein and acts on both yeast and Drosophila RNA polymerase II during transcription of double-stranded dC-tailed templates. The stimulatory activity is specific for RNA polymerase II since it has no significant effect on the elongation properties of yeast RNA polymerase I or yeast RNA polymerase III. Elongation by RNA polymerase II can be stimulated by RNase H on dC-tailed templates; however, the stimulatory activity of YES is not due to RNase H activity. YES does not stimulate RNA polymerase II in the presence of manganese ions and therefore is distinct from the smaller elongation factor, S-II or DmS-II. YES is most similar to Drosophila factor 5 (mammalian TFIIF, or RAP30/74), an initiation factor that is also able to increase the rate of elongation of RNA polymerase II.
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PMID:Identification and purification of a yeast protein that affects elongation by RNA polymerase II. 185 Nov 72

Transcription factor TFIIB is a ubiquitous factor required for transcription initiation by RNA polymerase II. Previous studies have suggested that TFIIB serves as a bridge between the "TATA"-binding factor (TFIID) and RNA polymerase II during preinitiation complex assembly and, more recently, that TFIIB can be a target of acidic activators. We have purified TFIIB to homogeneity, shown that activity resides in a 33-kDa polypeptide, and obtained cDNAs encoding functional TFIIB. TFIIB contains a region with amino acid sequence similarity to a highly conserved region of prokaryotic sigma factors. This is consistent with analogous functions for these factors in promoter recognition by RNA polymerases and with similar findings for TFIID, TFIIE, and TFIIF/RAP30. Like TFIID, TFIIB contains both a large imperfect repeat that could contribute an element of symmetry to the folded protein and clusters of basic residues that could interact with acidic activator domains. These findings argue for a common origin of TFIIB, TFIID, and other general transcription factors and for the evolutionary segregation of complementary functions.
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PMID:Sequence of general transcription factor TFIIB and relationships to other initiation factors. 194 68

A general initiation factor, TFIIE, is essential for transcription initiation by RNA polymerase II in conjunction with other general factors. TFIIE is a heterotetramer containing two subunits of relative molecular mass 57,000 (TFIIE-alpha) and two of 34,000 (TFIIE-beta). TFIIE-beta is required in conjunction with TFIIE-alpha for transcription initiation. Here we report the cloning and expression of a complementary DNA encoding a functional human TFIIE-beta. Recombinant TFIIE-beta could replace the natural TFIIE-beta for transcription in conjunction with TFIIE-alpha. Amino-acid sequence comparisons reveal regions with sequence similarities to: subregion 3 of bacterial sigma factors; a region of RAP30 (the small subunit of TFIIF) with sequence similarity to a sigma-factor subregion implicated in binding to RNA polymerase; and a portion of the basic region-helix-loop-helix motif found in several enhancer-binding proteins. These potential homologies have implications for the role of TFIIE in preinitiation complex assembly and function.
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PMID:Conserved sequence motifs in the small subunit of human general transcription factor TFIIE. 195 4


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