The minor capsid protein gp7 of bacteriophage SPP1 is required for efficient infection of Bacillus subtilis

Autor: Inês Vinga, Paulo Tavares, Rimantas Daugelavičius, Rudi Lurz, Anja Dröge, Asita C. Stiege, Mário A. Santos
Rok vydání: 2006
Předmět:
Zdroj: Molecular Microbiology. 61:1609-1621
ISSN: 1365-2958
0950-382X
DOI: 10.1111/j.1365-2958.2006.05327.x
Popis: Summary Gp7 is a minor capsid protein of the Bacillus subtilis bacteriophage SPP1. Homologous proteins are found in numerous phages but their function remained unknown. Deletion of gene 7 from the SPP1 genome yielded a mutant phage (SPP1del7) with reduced burst-size. SPP1del7 infections led to normal assem- bly of virus particles whose morphology, DNA and protein composition was undistinguishable from wild-type virions. However, only ~25% of the viral particles that lack gp7 were infectious. SPP1del7 particles caused a reduced depolarization of the B. subtilis membrane in infection assays suggesting a defect in virus genome traffic to the host cell. A higher number of SPP1del7 DNA ejection events led to abortive release of DNA to the culture medium when compared with wild-type infections. DNA ejec- tion in vitro showed that no detectable gp7 is co-ejected with the SPP1 genome and that its pres- ence in the virion correlated with anchoring of released DNA to the phage particle. The release of DNA from wild-type phages was slower than that from SPP1del7 suggesting that gp7 controls DNA exit from the virion. This feature is proposed to play a central role in supporting correct routing of the phage genome from the virion to the cell cytoplasm.
Databáze: OpenAIRE
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