A genetic analysis of an important hydrophobic interaction at the P22 tailspike protein N-terminal domain

Abstract

P22 bacteriophage has been studied extensively and has served as a model for many important processes such as in vivo protein folding, protein aggregation and protein-protein interactions. The trimeric tailspike protein (TSP) serves as the receptor-binding protein for the P22 bacteriophage to the bacterial host. The homotrimeric P22 tail consists of three chains of 666aa in which the first 108aa form a trimeric dome-like structure which is called the N-terminal domain (NTD) and is responsible for attachment of the tailspike protein to the rest of the phage particle structure in the phage assembly pathway. Knowledge of this interaction requires information on what amino acids are interacting in the interface and how the NTD structure is maintained. The first 23aa form the "stem peptide" which originates at the dome top and terminates at the dome bottom. It contains a hydrophobic valine patch (V8-V9-V10) located within the dome structure. It is hypothesized that the interaction between the hydrophobic valine patch located on stem peptide and the adjacent polypeptide is critical for the interchain interaction which should be important for the stability of the P22 TSP NTD itself. To test this hypothesis, each amino acid in the valine residues is substituted by an acid, a basic, and a hydrophobic amino acid. The results of such substitutions are presented as well as associated studies. The data strongly suggest that the valine patch is of critical importance in the hydrophobic interaction between stem peptide valine patch and an adjacent chain.

P22 Phage Shows Promising Antibacterial Activity Under Pathophysiological Conditions<strong> </strong>

“…Phage therapy is a strong potential candidate for the treatment of foodborne pathogens such as Salmonella typhimurium. The lytic Salmonella phage P22 has been widely studied but requires further study to be utilized as a standard treatment against Salmonella typhimurium (Marietto Gonçalves et al, 2011;Ahn et al, 2013;Ayariga et al, 2018). Our study provides insight into the pathophysiological characteristics that the phage P22 must withstand to be considered a viable therapeutic against Salmonella typhimurium.…”

Ɛ34 Phage Tailspike Protein is Resistant to Trypsin and Inhibits and Salmonella Biofilm Formation

“…Beta-sheet proteins similar to that in Ɛ34 TSP are known for their solenoid-shaped or elongated coil structure, typically having the β-strands running orthogonally to the long axis. Most of the P22-like phages such as P22, SF6, and E15 have been shown to possess this motif, which functions dually as a host receptor recognition structure and a LPS attachment and cleavage mechanism [111][112][113]. To engineer an antibacterial peptide or protein, there is the need to consider the physiological conditions as well as the gut conditions if the drug has to be taken orally.…”

Single Amino Acid Change Mutation in the Hydrophobic Core of the N-terminal Domain of P22 TSP affects the Proteins Stability

“…For instance, the SARS-CoV-2 has undergone several mutations, with some variants classified as "variants of concern," e.g., the Omicron and Delta variant of SARS-CoV-2 are known for their rapid transmission and antigenicity (5,6) due to mutation in the Spike protein. In our system, the P22 bacteriophage is a well-studied phage and has been used model phage for genetic, molecular, and structural studies (7,8,9,10,11). The phage possesses tail machinery, and attached to this tail machinery is an endorhamnosidase trimeric tailspike protein (TSP) that plays the role of a receptor-finding, receptor-binding, and a receptor processing protein for the phage (7,10).…”

“…In our system, the P22 bacteriophage is a well-studied phage and has been used model phage for genetic, molecular, and structural studies (7,8,9,10,11). The phage possesses tail machinery, and attached to this tail machinery is an endorhamnosidase trimeric tailspike protein (TSP) that plays the role of a receptor-finding, receptor-binding, and a receptor processing protein for the phage (7,10). It finds and binds to its host via the TSP.…”

“…This endorhamnosidase can specifically degrade the lipopolysaccharides of the host bacterial envelope leading to adsorbing, invading, replication in the host, and finally lysis of the host (14). The homotrimeric P22 TSP consists of three chains in which the N-terminal domain (NTD) which binds to the rest of the phage structure in the formation of a complete and infective phage (9), contains 108 amino acids (10). The NTD forms a trimeric dome-like structure that non-covalently attaches to the rest of the phage.…”