Interaction of the maturation protein of the bacteriophage MS2 and the F pilin of Escherichia coli

Antimicrobial resistance is a ever increasing global concern, with the lack of new antibiotics and misuse of current available antibiotics exacerbating the issue. An alternative approach is to use bacteriophages to infect bacteria and select against the resistant genes, allowing for existing stock to be used again. The maturation protein at the centre of the bacteriophage MS2 infects F plasmid containing bacteria including the entire \acrfull{ecoli}. The maturation protein in the centre of MS2 binds to the F pilus. This project investigates this interaction that delivers the viral DNA into bacteria. The model was ratified and extended through the use of protein-protein docking. A single subunit of the F pilus was compared to a trimer of subunits, and the trimer was found to be a more accurate model, as it included the steric hindrance of other monomer strands when approaching pilin attached to the maturation protein. Contacts between the maturation protein and F pilin were assesed during repeated Molecular Dynamics simulations, where the trimer model was shown to interact less, but within the same regions. Alanine scanning was performed before single-point mutations were made to explore making the maturation protein more versatile to other pili, without reducing the strength of binding to F pilin. After mutations, certain residues were found to be required for the maturation protein and F pilin to interact successfully. Other mutations had no effect on the interaction and some residues had a stronger interaction when mutated than before

Interaction of the maturation protein of the bacteriophage MS2 and the F pilin of Escherichia coli

Antimicrobial resistance is a ever increasing global concern, with the lack of new antibiotics and misuse of current available antibiotics exacerbating the issue. An alternative approach is to use bacteriophages to infect bacteria and select against the resistant genes, allowing for existing stock to be used again. The maturation protein at the centre of the bacteriophage MS2 infects F plasmid containing bacteria including the entire \acrfull{ecoli}. The maturation protein in the centre of MS2 binds to the F pilus. This project investigates this interaction that delivers the viral DNA into bacteria. The model was ratified and extended through the use of protein-protein docking. A single subunit of the F pilus was compared to a trimer of subunits, and the trimer was found to be a more accurate model, as it included the steric hindrance of other monomer strands when approaching pilin attached to the maturation protein. Contacts between the maturation protein and F pilin were assesed during repeated Molecular Dynamics simulations, where the trimer model was shown to interact less, but within the same regions. Alanine scanning was performed before single-point mutations were made to explore making the maturation protein more versatile to other pili, without reducing the strength of binding to F pilin. After mutations, certain residues were found to be required for the maturation protein and F pilin to interact successfully. Other mutations had no effect on the interaction and some residues had a stronger interaction when mutated than before

Interaction of the maturation protein of the bacteriophage MS2 and the sex pilus of the Escherichia coli F plasmid

© 2020 Elsevier Inc. One promising strategy to combat antimicrobial resistance is to use bacteriophages that attach to the sex pili produced by transmissible antimicrobial resistance (AMR) plasmids, infect AMR bacteria and select for loss of the AMR plasmids, prolonging the life of existing antimicrobials. The maturation protein of the bacteriophage MS2 attaches to the pili produced by Incompatibility group F plasmid-containing bacteria. This interaction initiates delivery of the viral genetic material into the bacteria. Using protein-protein docking we constructed a model of the F pilus comprising a trimer of subunits binding to the maturation protein. Interactions between the maturation protein and the F pilus were investigated using molecular dynamics simulations. In silico alanine scanning and in silico single-point mutations were explored, with the longer term aim of increasing the affinity of the maturation protein to other Incompatibility group pili, without reducing the strength of binding to F pilin. We report our computational findings on which residues are required for the maturation protein and F pilin to interact, those which had no effect on the interaction and the mutations which led to a stronger interaction