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Updated: Feb 7, 2026
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Isolation of F1-ATPase from the Parasitic Protist Trypanosoma brucei
Published on: January 22, 2019
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Molecular switch-like regulation enables global subunit coordination in a viral ring ATPase
Sara Tafoya1,2,3, Shixin Liu4, Juan P Castillo1,2
1Jason L. Choy Laboratory of Single Molecule Biophysics, University of California, Berkeley, CA 94720.
Summary
The bacteriophage φ29 DNA packaging motor uses two mechanisms to coordinate its subunits: DNA regulation and arginine fingers. These mechanisms ensure efficient motor function and may be common in other ring ATPases.
Area of Science:
- Biochemistry
- Molecular Biology
- Structural Biology
Background:
- Multimeric ring-shaped motors require subunit coordination for efficient mechanical task performance.
- The bacteriophage φ29 DNA packaging motor is a pentameric complex crucial for viral DNA replication.
Purpose of the Study:
- To investigate the molecular interactions coordinating the activities of subunits in the φ29 DNA packaging motor.
- To elucidate the roles of DNA and arginine fingers in the motor's biphasic mechanochemical cycle.
Main Methods:
- Studied wild-type (WT) and arginine finger mutants of the pentameric bacteriophage φ29 DNA packaging motor.
- Analyzed molecular interactions governing ADP-ATP exchange and ATP hydrolysis.
Main Results:
- Identified two distinct regulatory mechanisms for subunit coordination.
- DNA up-regulates a single subunit's catalytic activity, initiating nucleotide exchange and hydrolysis phases.
- Arginine fingers promote ADP-ATP exchange and ATP hydrolysis in neighboring subunits.
Conclusions:
- The φ29 motor subunits coordinate via DNA-mediated activation and inter-subunit arginine finger interactions.
- These mechanisms resemble GDP exchange factors and GTPase-activating proteins in small GTPases.
- Proposed fundamental mechanisms for intersubunit coordination in ring ATPases.
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