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)

The general transcription factor TFIIE has an essential role in eukaryotic transcription initiation together with RNA polymerase II and other general factors. Human TFIIE consists of two subunits of relative molecular mass 57,000 (TFIIE-alpha) and 34,000 (TFIIE-beta) and joins the preinitiation complex after RNA polymerase II and TFIIF. Here we report the cloning and structure of a complementary DNA encoding a functional human TFIIE-alpha. TFIIE-alpha is necessary for transcription initiation together with TFIIE-beta, and recombinant TFIIE-alpha can fully replace the natural subunit in an in vitro transcription assay. The sequence contains several interesting structural motifs (leucine repeat, zinc finger and helix-turn-helix) and sequence similarities to bacterial sigma factors that suggest direct involvement in the regulation of transcription initiation.
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PMID:Structural motifs and potential sigma homologies in the large subunit of human general transcription factor TFIIE. 195 3

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

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 general transcription factor TFIIE recruits TFIIH at a late stage of transcription initiation complex formation and markedly stimulates TFIIH-dependent phosphorylation of the carboxy-terminal domain (CTD) of RNA polymerase II. To study this function of TFIIE in more detail, systematic deletion mutations were introduced into the large subunit of TFIIE (TFIIE-alpha) and were analyzed with regard to their effects on TFIIH-dependent CTD phosphorylation, TFIIE-dependent basal and enhancer-dependent transcription, and interactions of TFIIE-alpha with both TFIIE-beta and TFIIH. The amino (N)-terminal half of TFIIE-alpha, which possesses several putative structural motifs, was sufficient for the phosphorylation and transcription activities and for TFIIE-beta interactions, whereas a site effecting both strong interactions with TFIIH and large stimulatory effects on transcription and CTD phosphorylation was localized to an acidic region near the carboxy (C) terminus. The fact that these activities appear to be tightly linked supports the idea that TFIIE interacts physically and functionally with TFIIH and that CTD phosphorylation is essential for transcription under normal conditions. The present results suggest that TFIIE, via its effect on TFIIH, may act as a checkpoint for formation of a preinitiation complex.
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PMID:Analysis of the role of TFIIE in basal transcription and TFIIH-mediated carboxy-terminal domain phosphorylation through structure-function studies of TFIIE-alpha. 765 4

General transcription factors are required for accurate initiation of transcription by RNA polymerase II. Human cDNAs encoding subunits of these factors have been cloned and sequenced. Using fluorescence in situ hybridization (FISH), we show here that the genes encoding the TATA-box binding protein (TBP), TFIIB, TFIIE alpha, TFIIE beta, RAP30, RAP74 and the 62 kDa subunit, of TFIIH are located at the human chromosomal bands 6q26-27, 1p21-22, 3q21-24, 8p12, 13q14, 19p13.3 and 11p14-15.1, respectively. This dispersed localization of a group of functionally related gene provides insights into the molecular mechanism of human genome evolution and their possible involvement in human diseases.
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PMID:Genes encoding general initiation factors for RNA polymerase II transcription are dispersed in the human genome. 816 52

The general transcription factor TFIIE, together with other general transcription factors, is essential for transcription initiation by RNA polymerase II. TFIIE stimulates the TFIIH-dependent kinase activity that phosphorylates the carboxy-terminal domain of the largest subunit of RNA polymerase II, and possesses a helicase activity. Here we show that human TFIIH has DNA-dependent ATPase activity and we characterize the stimulatory effect of TFIIE on both the ATPase and kinase activities. We demonstrate that extensive phosphorylation of RNA polymerase II occurs in a TFIIE-dependent manner in both the absence and presence of DNA but, in the latter case, only at a late stage of preinitiation complex assembly. We also show that TFIIH specifically phosphorylates three general transcription factors, human TFIID tau (TBP), TFIIE-alpha and TFIIF-alpha (RAP74).
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PMID:Regulation of TFIIH ATPase and kinase activities by TFIIE during active initiation complex formation. 816 91

The transcription/DNA repair factor TFIIH consists of nine subunits, several exhibiting known functions: helicase/ATPase, kinase activity and DNA binding. Three subunits of TFIIH, cdk7, cyclin H and MAT1, form a ternary complex, cdk-activating kinase (CAK), found either on its own or as part of TFIIH. In the present work, we demonstrate that purified human CAK complex (free CAK) and recombinant CAK (rCAK) produced in insect cells exhibit a strong preference for the cyclin-dependent kinase 2 (cdk2) over a ctd oligopeptide substrate (which mimics the carboxy-terminal domain of the RNA polymerase II). In contrast, TFIIH preferentially phosphorylates the ctd as well as TFIIE alpha, but not cdk2. TFIIH was resolved into four subcomplexes: the kinase complex composed of cdk7, cyclin H and MAT1; the core TFIIH which contains XPB, p62, p52, p44 and p34; and two other subcomplexes in which XPD is found associated with either the kinase complex or with the core TFIIH. Using these fractions, we demonstrate that TFIIH lacking the CAK subcomplex completely recovers its transcriptional activity in the presence of free CAK. Furthermore, studies examining the interactions between TFIIH subunits provide evidence that CAK is integrated within TFIIH via XPB and XPD.
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PMID:Substrate specificity of the cdk-activating kinase (CAK) is altered upon association with TFIIH. 913 Jul 8

Initiation of eukaryotic mRNA transcription requires melting of promoter DNA with the help of the general transcription factors TFIIE and TFIIH. Here we define a conserved and functionally essential N-terminal domain in TFE, the archaeal homolog of the large TFIIE subunit alpha. X-ray crystallography shows that this TFE domain adopts a winged helix-turn-helix (winged helix) fold, extended by specific alpha-helices at the N and C termini. Although the winged helix fold is often found in DNA-binding proteins, we show that TFE is not a typical DNA-binding winged helix protein, because its putative DNA-binding face shows a negatively charged groove and an unusually long wing, and because the domain lacks DNA-binding activity in vitro. The groove and a conserved hydrophobic surface patch on the additional N-terminal alpha-helix may, however, allow for interactions with other general transcription factors and RNA polymerase. Homology modeling shows that the TFE domain is conserved in TFIIE alpha, including the potential functional surfaces.
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PMID:An extended winged helix domain in general transcription factor E/IIE alpha. 1367 66

The topological organization of a TATA binding protein-TFIIB-TFIIF-RNA polymerase II (RNAP II)-TFIIE-promoter complex was analyzed using site-specific protein-DNA photo-cross-linking of gel-purified complexes. The cross-linking results for the subunits of RNAP II were used to determine the path of promoter DNA against the structure of the enzyme. The results indicate that promoter DNA wraps around the mobile clamp of RNAP II. Cross-linking of TFIIF and TFIIE both upstream of the TATA element and downstream of the transcription start site suggests that both factors associate with the RNAP II mobile clamp. TFIIE alpha closely approaches promoter DNA at nucleotide -10, a position immediately upstream of the transcription bubble in the open complex. Increased stimulation of transcription initiation by TFIIE alpha is obtained when the DNA template is artificially premelted in the -11/-1 region, suggesting that TFIIE alpha facilitates open complex formation, possibly through its interaction with the upstream end of the partially opened transcription bubble. These results support the central roles of the mobile clamp of RNAP II and TFIIE in transcription initiation.
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PMID:Photo-cross-linking of a purified preinitiation complex reveals central roles for the RNA polymerase II mobile clamp and TFIIE in initiation mechanisms. 1472 58

Transcription factor IIE (TFIIE) is a general initiation and promoter escape factor for RNA polymerase II composed of p56 (TFIIE-alpha) and p34 (TFIIE-beta) subunits. Our laboratories experienced difficulty producing adequate quantities of recombinant human TFIIE-alpha for in vitro studies using available clones. We therefore re-engineered the TFIIE subunit production vectors and tested various Escherichia coli host strains to optimize expression. We report a much-improved system for production of pure, soluble, and active TFIIE complex for in vitro studies.
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PMID:Efficient production of recombinant human transcription factor IIE. 1500 67


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