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Transcription termination factor rho has three distinct structural domains
J W Dolan1, N F Marshall, J P Richardson
1Department of Chemistry, Indiana University, Bloomington 47405.
The Journal of Biological Chemistry
|April 5, 1990
Summary
Transcription termination factor rho has three domains: RNA-binding, ATP-binding, and an unidentified carboxyl-terminal domain. These domains interact closely, influencing rho
Area of Science:
- Molecular Biology
- Biochemistry
Background:
- Transcription termination is a critical regulatory process in gene expression.
- The Rho (ρ) transcription termination factor plays a key role in bacterial termination.
Purpose of the Study:
- To elucidate the domain structure and functional organization of the Rho transcription termination factor.
- To identify the specific binding sites for RNA and ATP within the Rho subunit.
Main Methods:
- Partial trypsin cleavage of Rho subunits.
- Photoaffinity labeling using ATP and oligo(C)5.
Main Results:
- Rho subunit comprises three distinct domains: amino-terminal (RNA-binding), middle (ATP-binding), and carboxyl-terminal (function unidentified).
- The amino-terminal domain binds oligo(C)5, showing similarity to RNA-binding proteins.
- The middle domain contains the ATP-binding site, with similarities to nucleoside triphosphate-binding proteins.
- ATP and ADP inhibit cleavage between the amino-terminal and middle domains, suggesting intimate interaction.
Conclusions:
- Rho factor possesses a modular domain structure crucial for its function.
- The RNA-binding and ATP-binding domains interact closely, despite distinct functions.
- Further research is needed to determine the function of the carboxyl-terminal domain.