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)

RNA polymerase II will efficiently initiate transcription on linear duplex DNA which has been extended at its 3' ends by the addition of short stretches of polydeoxycytidine (Kadesch, T. R., and Chamberlin, M. J. (1982) J. Biol. Chem. 257, 5286-5295). We have used such dC-tailed templates to identify factors affecting elongation by Drosophila RNA polymerase II (Price, D. H., Sluder, A. E., and Greenleaf, A. L. (1987) J. Biol. Chem. 262, 3244-3255). While studying these factors we have observed two unexpected characteristics of transcription of the tailed templates. First, we found that RNA polymerase II encountered a strong pause site after the incorporation of 14 nucleotides. This pausing was observed on all templates examined and with RNA polymerase II from a variety of sources. In addition, we found that ammonium ions markedly stimulated the polymerase, increasing both the efficiency with which the enzyme left the 14 base pause site and the subsequent rate of elongation. A factor previously shown to affect transcription of dC-tailed templates (factor 4, Price, D. H., Sluder, A. E., and Greenleaf, A. L. (1987) J. Biol. Chem. 262, 3244-3255) was found to cause transcript displacement and to stimulate the elongation rate approximately 2-fold. This factor copurified with an RNase H activity, and a model is presented for the mechanism of transcript displacement by RNase H. The observations presented here form a basis for further analysis of RNA polymerase II elongation and its modulation by transcription factors. They should also aid in the interpretation of other experiments in which dC-tailed templates are used.
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PMID:Elongation by Drosophila RNA polymerase II. Transcription of 3'-extended DNA templates. 245 24

A phosphocellulose flowthrough fraction required for accurate transcription in vitro by RNA polymerase II was found to contain a DNase inhibitor which was necessary to maintain template integrity (Price D.H., Sluder A.E. & Greenleaf A.L. (1987) J. Biol. Chem. 262, 3244-3255). Starting with a Drosophila Kc cell nuclear extract, the DNase inhibitory activity has been purified 19,000-fold. In combination with the other necessary fractions, the highly purified inhibitor continues to support reconstruction of transcription. It thus appears to be the only required activity in the original phosphocellulose flowthrough fraction. The inhibitor is a protein which does not bind to DNA or inhibit DNase I, so that it has also been useful in assays for DNA binding proteins in crude, DNase-contaminated fractions.
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PMID:An activity necessary for in vitro transcription is a DNase inhibitor. 312 25

Factor 2 was previously identified in Drosophila Kc cell nuclear extract (KcN) as an activity suppressing the appearance of long transcripts (Price, D. H., Sluder, A. E., and Greenleaf, A. L. (1987) J. Biol. Chem. 262, 3244-3255). A 154-kDa protein with factor 2 activity was purified to apparent homogeneity from KcN. An immobilized template assay indicated that factor 2 caused the release of transcripts by RNA polymerase II in an ATP-dependent manner. Some early elongation complexes were resistant to factor 2 action but became sensitive after treatment with 1 M KCl. In the absence of factor 2, transcription complexes still exhibited a low degree of processivity suggesting that factor 2 was only partially responsible for abortive elongation.
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PMID:Purification of an RNA polymerase II transcript release factor from Drosophila. 862 43