Selection and structure of hyperactive inteins: peripheral changes relayed to the catalytic center
Kaori Hiraga1, Ikko Soga, John T Dansereau
1Wadsworth Center, New York State Department of Health, 150 New Scotland Avenue, Albany, NY 12208, USA.
Journal of Molecular Biology
|September 12, 2009
Summary
Inteins are self-splicing proteins. Researchers developed a phage display system to enhance intein function, discovering mutations in surface residues that allosterically improve splicing activity for biotechnological applications.
Area of Science:
- Biochemistry and Molecular Biology
- Protein Engineering
- Structural Biology
Background:
- Inteins are self-splicing proteins with diverse functions and applications in biotechnology and medicine.
- Understanding the structure-function relationship of inteins is crucial for optimizing their activity.
- Current methods for intein engineering primarily rely on in vivo selection.
Purpose of the Study:
- To develop an in vitro selection system using phage display to engineer inteins with enhanced function.
- To investigate the relationship between intein structure and splicing activity regulation.
- To identify mutations that improve intein performance under various environmental conditions.
Main Methods:
- Development of a phage display system for in vitro selection of inteins.
- Isolation and characterization of intein mutants with enhanced splicing activity.
- Crystallography and Nuclear Magnetic Resonance (NMR) spectroscopy to determine the structures of selected mutants.
Main Results:
- Successfully isolated inteins functional under extreme temperature, pH, and denaturing conditions.
- Identified mutations primarily on the intein surface, distant from the active site.
- Structural analyses revealed a 'ripple effect' where peripheral mutations allosterically enhance active-site function.
- Observed altered salt-bridge formation and chemical shift changes correlating with enhanced splicing activity.
Conclusions:
- The phage display system enables efficient in vitro selection for improved intein function.
- Peripheral mutations can allosterically modulate intein activity, providing a novel engineering strategy.
- These findings offer fundamental insights for advancing intein applications in chemical biology, biotechnology, and medicine.
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