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

---

Query: EC:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

BTF2/TFIIH from human, delta from rat, and factor b from yeast are multisubunit basal transcription factors that have been shown to be closely associated with a protein kinase capable of phosphorylating the carboxyl-terminal domain of the large subunit of RNA polymerase II (Lu, H., Zawel, L., Fischer, L., Egly, J. M., and Reinberg, D. (1992) Nature 358, 641-645; Serizawa, H., Conaway, R. C., and Conaway, J. W. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 7476-7480; Feaver, W. J., Gileadi, O., and Kornberg, R. D. (1991) Cell 67, 1223-1230). We report here that a DNA-dependent ATPase and the previously characterized helicase (Schaeffer, L., Roy, R., Humbert, S., Moncollin, V., Vermeulen, W., Hoeijmakers, J., Chambon, P., and Egly, J. M. (1993) Science 260, 58-63) are both associated with BTF2 and reside with the p89 polypeptide subunit. The DNA requirement, the effect of Sarkosyl and staurosporine inhibitors, as well as nucleotide competition experiments, clearly distinguished ATPase/helicase from the carboxyl-terminal domain kinase. Using recombinant wild type or mutated p89/ERCC3 polypeptides and different forms of DNA template, we show the connection between ATPase and the helicase.
...
PMID:The DNA-dependent ATPase activity associated with the class II basic transcription factor BTF2/TFIIH. 751 95

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).
...
PMID:Regulation of TFIIH ATPase and kinase activities by TFIIE during active initiation complex formation. 816 91

The human ERCC3 gene, which corrects specifically the nucleotide excision repair defect in human xeroderma pigmentosum group B and cross-complements the repair deficiency in rodent UV-sensitive mutants of group 3, encodes a presumed DNA helicase that is identical to the p89 subunit of the general transcription factor TFIIH/BTF2. To examine the significance of the postulated functional domains in ERCC3, we have introduced mutations in the ERCC3 cDNA by means of site-specific mutagenesis and have determined the repair capacity of each mutant to complement the UV-sensitive phenotype of rodent group 3 cells. A conservative substitution of arginine for the invariant lysine residue in the ATPase motif (helicase domain I), six deletion mutations in the other helicase domains, and a deletion in the potential helix-turn-helix DNA-binding motif fail to complement the ERCC3 excision repair defect of rodent group 3 mutants, which implies that the helicase domains as well as the potential DNA-binding motif are required for the repair function of ERCC3. Analysis of carboxy-terminal deletions suggests that the carboxy-terminal exon may comprise a distinct determinant for the DNA repair function. In addition, we show that a functional epitope-tagged version of ERCC3 accumulates in the nucleus. Deletion of the putative nuclear location signal impairs neither the nuclear location nor the repair function, indicating that other sequences may (also) be involved in translocation of ERCC3 to the nucleus.
...
PMID:Mutational analysis of ERCC3, which is involved in DNA repair and transcription initiation: identification of domains essential for the DNA repair function. 819 50

Yeast RNA polymerase II initiation factor b, homolog of human TFIIH, is a protein kinase capable of phosphorylating the C-terminal repeat domain of the polymerase; it possesses a DNA-dependent ATPase activity as well. The 85 kd and 50 kd subunits of factor b are now identified as RAD3 and SSL1 proteins, respectively; both are known to be involved in DNA repair. Factor b interacts specifically with another DNA repair protein, SSL2. The ATPase activity of factor b may be due entirely to that associated with a helicase function of RAD3. Factor b transcriptional activity was unaffected, however, by amino acid substitution at a conserved residue in the RAD3 nucleotide-binding domain, suggesting that the ATPase/helicase function is not required for transcription. These results identify factor b as a core repairosome, which may be responsible for the preferential repair of actively transcribed genes in eukaryotes.
...
PMID:Dual roles of a multiprotein complex from S. cerevisiae in transcription and DNA repair. 826 16

RNA polymerase II initiation factor delta was previously purified from rat liver and found to possess a closely associated DNA-dependent ATPase activity and a protein kinase activity capable of phosphorylating the carboxyl-terminal domain (CTD) of the largest subunit of RNA polymerase II (Serizawa, H., Conaway, R.C., and Conaway, J.W. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 7476-7480). In addition, delta's human homolog, BTF2(TFIIH), was recently shown to have an associated DNA helicase activity (Schaeffer, L., Roy, R., Humbert, S., Moncollin, V., Vermeulen, W., Hoeijmakers, J.H.J., Chambon, P., and Egly, J.-M. (1993) Science 259, 58-63). Here we demonstrate that initiation factor delta also possesses DNA helicase activity. In addition, we compare the properties of delta's associated CTD kinase, ATPase, and DNA helicase activities. Whereas the enzymatic properties of ATPase and DNA helicase are similar and consistent with the possibility that they could function in ATP-dependent activation of the preinitiation complex, ATPase and CTD kinase exhibit significant differences in their nucleotide specificities, responses to DNA effectors, and sensitivities to inhibitors.
...
PMID:Multifunctional RNA polymerase II initiation factor delta from rat liver. Relationship between carboxyl-terminal domain kinase, ATPase, and DNA helicase activities. 839 38

XPB is a subunit of the basal transcription factor TFIIH, which is also involved in nucleotide excision repair (NER) and potentially in cell cycle regulation. A frameshift mutation in the 3'-end of the XPB gene is responsible for a concurrence of two disorders: xeroderma pigmentosum (XP) and Cockayne's syndrome (CS). We have isolated TFIIH from cells derived from a patient (XP11BE) who carries this frameshift mutation (TFIIHmut) and from the mother of this patient (TFIIHwt) to determine the biochemical consequences of the mutation. Although identical in composition and stoichiometry to TFIIHwt, TFIIHmut shows a reduced 3' --> 5' XPB helicase activity. A decrease in helicase and DNA-dependent ATPase activities was also observed with the mutated recombinant XPB protein. The XPB mutation causes a severe NER defect. In addition, we provide evidence for a decrease in basal transcription activity in vitro. The latter defect may provide an explanation for many of the XP and CS symptoms that are difficult to rationalize based solely on an NER defect. Thus, this work presents the first detailed analysis of a naturally occurring mutation in a basal transcription factor and supports the concept that the combined XP/CS clinical entity is actually the result of a combined transcription/repair deficiency.
...
PMID:A 3' --> 5' XPB helicase defect in repair/transcription factor TFIIH of xeroderma pigmentosum group B affects both DNA repair and transcription. 866 48

Transcription is coupled to repair in Escherichia coli and in humans. Proteins encoded by the mfd gene in E. coli and by the ERCC6/CSB gene in humans, both of which possess the so-called helicase motifs, are required for the coupling reaction. It has been shown that the Mfd protein is an ATPase but not a helicase and accomplishes coupling, in part, by disrupting the ternary complex of E. coli RNA polymerase stalled at the site of DNA damage. In this study we overproduced the human CSB protein using the baculovirus vector and purified and characterized the recombinant protein. CSB has an ATPase activity that is stimulated strongly by DNA; however, it neither acts as a helicase nor does it dissociate stalled RNA polymerase II, suggesting a coupling mechanism in humans different from that in prokaryotes. CSB is a DNA-binding protein, and it also binds to XPA, TFIIH, and the p34 subunit of TFIIE. These interactions are likely to play a role in recruiting repair proteins to ternary complexes formed at damage sites.
...
PMID:Human transcription-repair coupling factor CSB/ERCC6 is a DNA-stimulated ATPase but is not a helicase and does not disrupt the ternary transcription complex of stalled RNA polymerase II. 899 76

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.
...
PMID:Substrate specificity of the cdk-activating kinase (CAK) is altered upon association with TFIIH. 913 Jul 8

TFIIH is a multifunctional RNA polymerase II transcription factor that possesses DNA-dependent ATPase, DNA helicase, and protein kinase activities. Previous studies have established that TFIIH enters the preinitiation complex and fulfills a critical role in initiation by catalyzing ATP-dependent formation of the open complex prior to synthesis of the first phosphodiester bond of nascent transcripts. In this report, we present direct evidence that TFIIH also controls RNA polymerase II activity at a postinitiation stage of transcription, by preventing premature arrest by very early elongation complexes just prior to their transition to stably elongating complexes. Unexpectedly, we observe that TFIIH is capable of entering the transcription cycle not only during assembly of the preinitiation complex but also after initiation and synthesis of as many as four to six phosphodiester bonds. These findings shed new light on the role of TFIIH in initiation and promoter escape and reveal an unanticipated flexibility in the ability of TFIIH to interact with RNA polymerase II transcription intermediates prior to, during, and immediately after initiation.
...
PMID:A role for TFIIH in controlling the activity of early RNA polymerase II elongation complexes. 925 25

TFIIH is a high molecular weight complex with a remarkable dual function in nucleotide excision repair and initiation of RNA polymerase II transcription. Mutations in the largest subunits, the XPB and XPD helicases, are associated with three inherited disorders: xeroderma pigmentosum, Cockayne's syndrome, and trichothiodystrophy. To facilitate the purification and biochemical characterization of this intricate complex, we generated a cell line stably expressing tagged XPB, allowing the immunopurification of the XPB protein and associated factors. Addition of two tags, a N-terminal hexameric histidine stretch and a C-terminal hemagglutinin epitope, to this highly conserved protein did not interfere with its functioning in repair and transcription. The hemagglutinin epitope allowed efficient TFIIH immunopurification to homogeneity from a fractionated whole cell extract in essentially one step. We conclude that the predominant active form of TFIIH is composed of nine subunits and that there is one molecule of XPB per TFIIH complex. The affinity-purified complex exhibits all expected TFIIH activities: DNA-dependent ATPase, helicase, C-terminal domain kinase, and participation in in vitro and in vivo nucleotide excision repair and in vitro transcription. The affinity purification procedure described here is fast and simple, does not require extensive chromatographic procedures, and yields highly purified, active TFIIH.
...
PMID:Affinity purification of human DNA repair/transcription factor TFIIH using epitope-tagged xeroderma pigmentosum B protein. 942 74


1 2 3 4 Next >>

---