Protein structure. Engineering of a superhelicase through conformational control

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Biomolecular activity is often regulated by conformational changes.
• Understanding these conformational controls can provide functional insights and enable novel engineering.
• Helicases are enzymes crucial for nucleic acid metabolism, but their activity is tightly regulated.

Purpose of the Study:

• To investigate the role of conformational control in helicase activity.
• To engineer a highly active monomeric helicase through conformational manipulation.
• To explore the mechanism of a natural helicase activity enhancer.

Main Methods:

• Intramolecular cross-linking of a monomeric helicase.
• Biophysical characterization of the engineered helicase.
• Assays to measure nucleic acid unwinding activity and processivity.
• Structural analysis of the helicase-partner interaction.

Main Results:

• Intramolecular cross-linking converted a low-activity helicase monomer into a processive super helicase.
• The engineered super helicase could unwind thousands of base pairs against significant opposing force.
• A natural helicase partner was found to enhance activity by stabilizing the active conformation.
• The engineered super helicase lacks nuclease activities.

Conclusions:

• Conformational control is a powerful strategy for engineering enzyme activity.
• A monomeric super helicase with high processivity and no nuclease activity has been developed.
• This engineered enzyme holds promise for various biotechnological applications requiring efficient nucleic acid unwinding.