Multiple RNA Polymerase Conformations and GreA: Control of the Fidelity of Transcription
| Autor: | Mark Young, Omid Hajiseyedjavadi, Dorothy A. Erie, P H von Hippel |
|---|---|
| Rok vydání: | 1993 |
| Předmět: |
Enzyme complex
Transcription Genetic Protein Conformation Molecular Sequence Data Uridine Triphosphate RNA polymerase II Biology chemistry.chemical_compound Transcription (biology) RNA polymerase Endoribonucleases Escherichia coli RNA Messenger Multidisciplinary Base Sequence Models Genetic General transcription factor Nucleotides Escherichia coli Proteins RNA DNA-Directed RNA Polymerases Templates Genetic Peptide Elongation Factors Kinetics Biochemistry chemistry Transcription preinitiation complex biology.protein Biophysics Transcription factor II D Transcription Factors |
| Zdroj: | Science. 262:867-873 |
| ISSN: | 1095-9203 0036-8075 |
| DOI: | 10.1126/science.8235608 |
| Popis: | Pre-steady state kinetics of misincorporation were used to investigate the addition of single nucleotides to nascent RNA by Escherichia coli RNA polymerase during transcription elongation. The results were fit with a branched kinetic mechanism that permits conformational switching, at each template position, between an activated and an unactivated enzyme complex, both of which can bind nucleotide triphosphates (NTPs) from solution. The complex exists most often in the long-lived activated state, and only becomes unactivated when transcription is slowed. This model permits multiple levels of nucleotide discrimination in transcription, since the complex can be "kinetically trapped" in the unactivated state in the absence of the correct NTP or if the 3' terminal residue is incorrectly matched. The transcription cleavage factor GreA (or an activity enhanced by GreA) increased the fidelity of transcription by preferential cleavage of transcripts containing misincorporated residues in the unactivated state of the elongation complex. This cleavage mechanism by GreA may prevent the formation of "dead-end" transcription complexes in vivo. |
| Databáze: | OpenAIRE |
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