Characterization of a Lambdoid Phage Gene Encoding a Host Cell Attachment Spike
The first and most crucial step in a bacteriophage's life cycle is the adsorption step. This step entails docking on to the phage's host and inserting its genetic material into the host cell. Should this first important step not occur, the phage will remain an inert particle in the environment until a more suitable host is found. For the lambdoid phage, ?80, this is a two step process. An initial reversible adsorption results from docking to the outer membrane siderophore transporter FhuA by weak electrostatic interactions. Additionally, a second nonreversible step requires the presence of TonB and a functional proton motive force. Although adsorption process of ?80 has been determined, the phage protein that mediates this process has not been characterized. This thesis describes the means of finding and characterizing the open reading frame responsible for the production of the ?80 tail spike. Once found, the predicted product of this open reading frame was subjected to proteomic analyses to determine sequence similarities to other lambdoid phage and phage that require FhuA and/or TonB for their adsorption process. Like the phage ?, the putative spike protein of ?80 was predicted to have a functional domain near the carboxyl terminus that mediates receptor binding to FhuA. Additionally, a putative TonB box was predicted in the amino terminus that allows for the interaction with TonB, providing energy for the uptake of the phage genome.
School:Bowling Green State University
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:?80 lambdoid phage fhua tonb host range specificity
Date of Publication:01/01/2008