Nonsense mutants of bacteriophage φ6 were isolated by a procedure that involved directed mutagenesis of a cDNA copy of genomic segment M, transcription of this segment, in vitro packaging into procapsids, and transfection of spheroplasts to form viable mutant phage. Recombinant φ6 viruses that contained amber mutations in two open reading frames, ORF 10 and ORF D, of genomic segment M were isolated. We show that φ6 protein P10 is the gene product of ORF 10. Further characterization of the φ6 ORF 10(Am) mutant revealed that φ6 membrane-associated protein P10 is not required to make enveloped phage particles in infected cells. Enveloped phage particles isolated from a φ6 ORF 10(Am) infection contained extremely low levels of φ6 membrane-associated proteins P6 and P3. The low abundance is due to the very low level of P6 synthesis in φ6 ORF 10(Am)-infected cells. The results suggest that P10 might play a role in regulating the translation of gene 6. Protein P10 was found to be required for host lysis.
All Science Journal Classification (ASJC) codes
- Insect Science