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Published on: October 14, 2011
Early intermediates in bacteriophage lambda prohead assembly. II. Identification of biologically active intermediates
Virology
|November 1, 1983
Summary
Bacteriophage lambda prohead assembly involves specific phage and E. coli genes. This study identifies key protein intermediates, including a major gpB polymer and a minor gpB-GroEL complex, crucial for forming infectious phage particles.
Area of Science:
- Molecular Biology
- Virology
- Structural Biology
Background:
- Bacteriophage lambda prohead morphogenesis is regulated by phage genes (B, C, Nu3, E) and E. coli genes (GroEL, GroES).
- Previous studies showed accumulation of active gpB and gpNu3 in lambda C-E- mutant infections.
Purpose of the Study:
- To characterize the nature of protein intermediates in bacteriophage lambda prohead assembly.
- To identify the specific forms of gpB involved in the assembly process.
Main Methods:
- Fractionation of cell extracts using DEAE-cellulose chromatography and velocity sedimentation.
- Identification of intermediates via SDS-polyacrylamide gel electrophoresis.
- Assessment of biological activity through in vitro assembly into infectious proheads.
Main Results:
- The predominant biologically active intermediate (over 98% of gpB activity) is a 25S gpB-containing polymer.
- A minor biologically active intermediate (around 1% of gpB activity) was identified as a gpB-GroEL complex.
Conclusions:
- The 25S gpB polymer is the primary intermediate in bacteriophage lambda prohead assembly.
- A gpB-GroEL complex also plays a role, albeit minor, in the assembly pathway.
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