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Membrane-mediated assembly of filamentous bacteriophage Pf1 coat protein
R Nambudripad1, W Stark, S J Opella
1Department of Physics, Boston University, MA 02215.
Abstract:
Filamentous bacteriophage Pf1 assembles by a membrane-mediated process during which the viral DNA is secreted through the membrane while being encapsulated by the major coat protein. Neutron diffraction studies showed that in the virus most of the coat protein consists of two alpha-helical segments arranged end-to-end with an intervening mobile surface loop. Nuclear magnetic resonance studies of the coat protein in the membrane-bound form have shown that the secondary structure is essentially identical to that in the intact virus. A comparison indicates that during membrane-mediated viral assembly, while the secondary structure of the coat protein is largely conserved, its tertiary structure changes substantially.
Insights
Filamentous bacteriophage Pf1 assembly involves membrane transport. While the coat protein
Area of Science:
- Structural biology
- Molecular biology
- Virology
Background:
- Filamentous bacteriophage Pf1 assembly is a membrane-mediated process.
- Viral DNA is secreted and encapsulated by the major coat protein during assembly.
Purpose of the Study:
- To investigate the structural changes of the Pf1 coat protein during viral assembly.
Main Methods:
- Neutron diffraction studies of intact virus.
- Nuclear magnetic resonance (NMR) studies of membrane-bound coat protein.
Main Results:
- The Pf1 coat protein in the intact virus features two alpha-helical segments with a mobile surface loop.
- The secondary structure of the coat protein remains consistent between the intact virus and membrane-bound forms.
- Significant changes in tertiary structure occur during membrane-mediated viral assembly.
Conclusions:
- The secondary structure of the Pf1 coat protein is conserved during assembly.
- Tertiary structure undergoes substantial alterations, facilitating membrane-mediated viral assembly.