Temperate bacteriophage can adopt either a lytic or a lysogenic lifestyle. In the lytic lifestyle, the bacteriophage infects a cell, uses the host's cellular machinery to replicate, and lyses the cell to release the phage progeny. In the lysogenic lifestyle the bacteriophage genome is integrated into the bacterial genome to generate a prophage. Most of the genes of the prophage are repressed. However, those genes that are expressed have a wide variety of functions including exclusion, the prevention of phage infection. Lysogens of bacteriophage HK239 have the ability to exclude a wide variety of phage, including (lambda), T4rII, Plvir, P2, and HK022. The goal of this research was to understand how HK239 prevents the growth of this diverse group of phages, by identifying the gene or genes that are responsible for the exclusion function. To this end, a library of HK239 DNA fragments was constructed and transformed into Escherichia coli. After the transformants were screened for phage resistance, one clone was found to exclude HK022 and a (lambda)(q<)80 hybrid. The recombinant plasmid was isolated, and the sequence of the cloned DNA revealed the presence of a (q>)80 cor homolog. In (q>)80, the cor gene is responsible for preventing infection by rendering the phage binding site inaccessible.
Advisor(s) or Committee Chair
Dr. Rodney King
Wright, Ali, "Identifying Exclusion Genes of Bacteriophage HK239" (2006). Honors College Capstone Experience/Thesis Projects. Paper 3.