Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa

Pseudomonas aeruginosa is an opportunistic pathogen known to cause several infections such as respiratory tract infections, urinary tract infections (UTI) and sepsis. It is often associated with nosocomial infections, due to its ability to form biofilms on medical equipment such as ventilators, cath...

Full description

Bibliographic Details
Main Author: Newman, Christopher James
Format: Thesis (University of Nottingham only)
Language:English
Published: 2017
Subjects:
Online Access:https://eprints.nottingham.ac.uk/42888/
_version_ 1848796593543708672
author Newman, Christopher James
author_facet Newman, Christopher James
author_sort Newman, Christopher James
building Nottingham Research Data Repository
collection Online Access
description Pseudomonas aeruginosa is an opportunistic pathogen known to cause several infections such as respiratory tract infections, urinary tract infections (UTI) and sepsis. It is often associated with nosocomial infections, due to its ability to form biofilms on medical equipment such as ventilators, catheters and cannulas. P. aeruginosa produces bacteriocins that kill related strains of bacteria and have potential implications as alternative antimicrobial therapy. One such bacteriocin is the S3 pyocin, which consists of 2 proteins, a a multi domain DNAse, and an immunity protein. Comparison of the DNase domains of S3 with other S type pyocins such as pyocin S1, S2, AP41 suggested that the DNase of S3 was atypical and did not have the characteristic zinc finger binding HNH motif. The DNase/Im encoding genes were cloned into the expression vector, pET21a and the DNAse/Immunity protein complex was purified using His-Tag and gel filtration chromatography. The DNAse was then separated from the Immunity protein by protein denaturation of the complex with guanidine and the DNAse activity of pyocin S3 was confirmed by its cleavage of plasmid DNA which was inhibited by the addition of the Immunity protein. Crystallisation trials were performed, and crystals were produced in a range of conditions. A selection of high quality, large crystals returned a resolution of 1.55-1.75Å from X-ray analysis via synchrotron but lack of phase data meant that the protein structure of the DNase/Im complex is still under investigation.
first_indexed 2025-11-14T19:50:27Z
format Thesis (University of Nottingham only)
id nottingham-42888
institution University of Nottingham Malaysia Campus
institution_category Local University
language English
last_indexed 2025-11-14T19:50:27Z
publishDate 2017
recordtype eprints
repository_type Digital Repository
spelling nottingham-428882025-02-28T13:46:24Z https://eprints.nottingham.ac.uk/42888/ Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa Newman, Christopher James Pseudomonas aeruginosa is an opportunistic pathogen known to cause several infections such as respiratory tract infections, urinary tract infections (UTI) and sepsis. It is often associated with nosocomial infections, due to its ability to form biofilms on medical equipment such as ventilators, catheters and cannulas. P. aeruginosa produces bacteriocins that kill related strains of bacteria and have potential implications as alternative antimicrobial therapy. One such bacteriocin is the S3 pyocin, which consists of 2 proteins, a a multi domain DNAse, and an immunity protein. Comparison of the DNase domains of S3 with other S type pyocins such as pyocin S1, S2, AP41 suggested that the DNase of S3 was atypical and did not have the characteristic zinc finger binding HNH motif. The DNase/Im encoding genes were cloned into the expression vector, pET21a and the DNAse/Immunity protein complex was purified using His-Tag and gel filtration chromatography. The DNAse was then separated from the Immunity protein by protein denaturation of the complex with guanidine and the DNAse activity of pyocin S3 was confirmed by its cleavage of plasmid DNA which was inhibited by the addition of the Immunity protein. Crystallisation trials were performed, and crystals were produced in a range of conditions. A selection of high quality, large crystals returned a resolution of 1.55-1.75Å from X-ray analysis via synchrotron but lack of phase data meant that the protein structure of the DNase/Im complex is still under investigation. 2017-07-17 Thesis (University of Nottingham only) NonPeerReviewed application/pdf en arr https://eprints.nottingham.ac.uk/42888/1/THESIS-MC-MODIFIED-FINAL.pdf Newman, Christopher James (2017) Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa. MRes thesis, University of Nottingham. Pseudomonas Pyocin Protein Purification Crystallography S3
spellingShingle Pseudomonas
Pyocin
Protein Purification
Crystallography
S3
Newman, Christopher James
Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa
title Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa
title_full Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa
title_fullStr Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa
title_full_unstemmed Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa
title_short Expression, purification and crystallisation of DNAse and immunity proteins in the S3 pyocin of Pseudomonas aeruginosa
title_sort expression, purification and crystallisation of dnase and immunity proteins in the s3 pyocin of pseudomonas aeruginosa
topic Pseudomonas
Pyocin
Protein Purification
Crystallography
S3
url https://eprints.nottingham.ac.uk/42888/