Studies on phage internal proteins: formation of internal protein - T2 DNA complexes in vivo

Area of Science:

• Molecular Biology
• Virology
• Bacteriology

Background:

• T-even phages infect Escherichia coli, utilizing bacterial machinery for replication.
• Bacterial internal proteins are synthesized post-infection and play roles in phage assembly.

Purpose of the Study:

• To investigate the fate and function of internal proteins during T2 phage infection.
• To identify protein-DNA complexes as potential intermediates in T-even phage morphogenesis.

Main Methods:

• Recovery of internal proteins from bacterial membranes of T2-infected Escherichia coli B cells.
• Analysis of protein-DNA complex formation using sedimentation and hydroxylapatite chromatography.
• Infection with amber mutants defective in specific genes (21, 22, 23) to assess protein release.

Main Results:

• T2 and T4 internal proteins were released from bacterial membranes approximately 15 minutes post-infection.
• Released internal proteins sedimented with newly synthesized phage DNA, forming complexes.
• Internal proteins failed to be released from membranes when infected with amber mutants in genes 21, 22, and 23.

Conclusions:

• Internal proteins form complexes with phage DNA, indicating their involvement in T-even phage assembly.
• These protein-DNA complexes are likely essential intermediates in the morphogenesis of T-even bacteriophages.