Novel mechanism of gene regulation: the protein Rv1222 of Mycobacterium tuberculosis inhibits transcription by anchoring the RNA polymerase onto DNA
| Autor: | Jayanta Mukhopadhyay, Paulami Rudra, Ranjit Kumar Prajapati, Shreya Sengupta, Rajdeep Banerjee |
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| Rok vydání: | 2015 |
| Předmět: |
DNA
Bacterial Transcription Genetic DNA polymerase II RNA polymerase II Sigma Factor DNA-Directed DNA Polymerase chemistry.chemical_compound Bacterial Proteins Transcription (biology) RNA polymerase Genetics Transcription bubble DNA clamp biology General transcription factor Gene regulation Chromatin and Epigenetics DNA-binding domain DNA-Directed RNA Polymerases Gene Expression Regulation Bacterial Mycobacterium tuberculosis Molecular biology Cell biology chemistry biology.protein RNA Protein Binding Transcription Factors |
| Zdroj: | Nucleic Acids Research |
| ISSN: | 1362-4962 |
| Popis: | We propose a novel mechanism of gene regulation in Mycobacterium tuberculosis where the protein Rv1222 inhibits transcription by anchoring RNA polymerase (RNAP) onto DNA. In contrast to our existing knowledge that transcriptional repressors function either by binding to DNA at specific sequences or by binding to RNAP, we show that Rv1222-mediated transcription inhibition requires simultaneous binding of the protein to both RNAP and DNA. We demonstrate that the positively charged C-terminus tail of Rv1222 is responsible for anchoring RNAP on DNA, hence the protein slows down the movement of RNAP along the DNA during transcription elongation. The interaction between Rv1222 and DNA is electrostatic, thus the protein could inhibit transcription from any gene. As Rv1222 slows down the RNA synthesis, upon expression of the protein in Mycobacterium smegmatis or Escherichia coli, the growth rate of the bacteria is severely impaired. The protein does not possess any significant affinity for DNA polymerase, thus, is unable to inhibit DNA synthesis. The proposed mechanism by which Rv1222 inhibits transcription reveals a new repertoire of prokaryotic gene regulation. |
| Databáze: | OpenAIRE |
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