Isolation and characterization of RNA polymerase rpoB mutations that alter transcription slippage during elongation in Escherichia coli
| Autor: | Carolyn Court, Shuo Chen, Monica P. Hui, Jeffrey N. Strathern, Ding Jun Jin, Lucyna Lubkowska, Donald L. Court, Mikhail Kashlev, Yan Ning Zhou |
|---|---|
| Rok vydání: | 2012 |
| Předmět: |
Transcription
Genetic Protein Conformation Molecular Sequence Data RNA polymerase II Biochemistry Chromosomes chemistry.chemical_compound Transcription (biology) RNA polymerase Transcriptional regulation Escherichia coli Gene Regulation Amino Acid Sequence RNA Messenger Molecular Biology Gene Genetics biology Base Sequence Models Genetic Sequence Homology Amino Acid Escherichia coli Proteins RNA Cell Biology DNA-Directed RNA Polymerases Protein Structure Tertiary Phenotype chemistry Lac Operon RNA editing Mutation biology.protein DNA Plasmids |
| Zdroj: | The Journal of biological chemistry. 288(4) |
| ISSN: | 1083-351X |
| Popis: | Transcription fidelity is critical for maintaining the accurate flow of genetic information. The study of transcription fidelity has been limited because the intrinsic error rate of transcription is obscured by the higher error rate of translation, making identification of phenotypes associated with transcription infidelity challenging. Slippage of elongating RNA polymerase (RNAP) on homopolymeric A/T tracts in DNA represents a special type of transcription error leading to disruption of open reading frames in Escherichia coli mRNA. However, the regions in RNAP involved in elongation slippage and its molecular mechanism are unknown. We constructed an A/T tract that is out of frame relative to a downstream lacZ gene on the chromosome to examine transcriptional slippage during elongation. Further, we developed a genetic system that enabled us for the first time to isolate and characterize E. coli RNAP mutants with altered transcriptional slippage in vivo. We identified several amino acid residues in the β subunit of RNAP that affect slippage in vivo and in vitro. Interestingly, these highly clustered residues are located near the RNA strand of the RNA-DNA hybrid in the elongation complex. Our E. coli study complements an accompanying study of slippage by yeast RNAP II and provides the basis for future studies on the mechanism of transcription fidelity. Background: The domains in RNA polymerase involved in elongation slippage are unknown. Results: We isolated E. coli RNA polymerase rpoB mutants with altered transcriptional slippage. Conclusion: The fork domain of RNA polymerase controls slippage. Biochemical analysis of the mutants validates the genetic schemes. Significance: Our work sheds light on the mechanism for maintenance of RNA-DNA register during transcription. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|