The molecular biology of chlamydiaphages
The molecular biology of chlamydiaphages
A novel bacteriophage was discovered during this study (Chp3). Chp3 infects a chlamydial species not previously known to carry bacteriophages (C. pecorum). The genome of Chp3 is 4.554 bp and encodes eight open reading frames that are organised in the same relative context as other chlamydiaphages. Chp3 is closely related to the Chp2-like bacteriophages. Interestingly while the VP1 of the Chp3-like bacteriophages remains highly conserved two regions show high divergence between Chp2-Chp3 and φCPG1/φCPAR39. It has been hypothesised that these regions are chlamydiaphage receptor-recognition domain. The host range of Chp3 is identical to the host range of Chp2 (C. abortus, C. pecorum, C. felis and C. caviae). φCPAR39 is also to infect C. abortus, C. caviae and C. pecorum, however, it is unable to infect C. felis and can additionally infect C. pneumoniae. This suggests that these two sub groups of chlamydiaphages use different surface receptor molecules.
It has been predicted that the chlamydiaphage genome is arranged into eight major open reading frames (ORF1-8). Immuno-specific reagents were produced to the proteins encoded by ORF2-8 and a monoclonal to VP1 was identified. These reagents were then used to screen Chp2 infected C. abortus inclusions and semi-purified Chp2 particles. The expression of VP1, VP3, ORF5 protein ORF4 protein and ORF7 protein was demonstrated.
It is likely that chlamydiaphages regulate their gene expression in a similar way to other bacteriophages in the Microviridae. By comparing the genome organisation of Chp2 to two members of this family of bacteriophages SpV4 and φX174 two promoter regions were identified in the Chp2 genome situated upstream of the ORF4 and ORF5 translational initiation codons. Using promoter selection vectors it was shown that these two promoter regions are functional in E. coli. The promoter situated upstream of the ORF5 translational initiation codon is a stronger E. coli promoter than the ORF4 promoter.
University of Southampton
Garner, Sarah Ann
22fd6597-6e72-4f74-832f-4a6f6276c66e
2003
Garner, Sarah Ann
22fd6597-6e72-4f74-832f-4a6f6276c66e
Garner, Sarah Ann
(2003)
The molecular biology of chlamydiaphages.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
A novel bacteriophage was discovered during this study (Chp3). Chp3 infects a chlamydial species not previously known to carry bacteriophages (C. pecorum). The genome of Chp3 is 4.554 bp and encodes eight open reading frames that are organised in the same relative context as other chlamydiaphages. Chp3 is closely related to the Chp2-like bacteriophages. Interestingly while the VP1 of the Chp3-like bacteriophages remains highly conserved two regions show high divergence between Chp2-Chp3 and φCPG1/φCPAR39. It has been hypothesised that these regions are chlamydiaphage receptor-recognition domain. The host range of Chp3 is identical to the host range of Chp2 (C. abortus, C. pecorum, C. felis and C. caviae). φCPAR39 is also to infect C. abortus, C. caviae and C. pecorum, however, it is unable to infect C. felis and can additionally infect C. pneumoniae. This suggests that these two sub groups of chlamydiaphages use different surface receptor molecules.
It has been predicted that the chlamydiaphage genome is arranged into eight major open reading frames (ORF1-8). Immuno-specific reagents were produced to the proteins encoded by ORF2-8 and a monoclonal to VP1 was identified. These reagents were then used to screen Chp2 infected C. abortus inclusions and semi-purified Chp2 particles. The expression of VP1, VP3, ORF5 protein ORF4 protein and ORF7 protein was demonstrated.
It is likely that chlamydiaphages regulate their gene expression in a similar way to other bacteriophages in the Microviridae. By comparing the genome organisation of Chp2 to two members of this family of bacteriophages SpV4 and φX174 two promoter regions were identified in the Chp2 genome situated upstream of the ORF4 and ORF5 translational initiation codons. Using promoter selection vectors it was shown that these two promoter regions are functional in E. coli. The promoter situated upstream of the ORF5 translational initiation codon is a stronger E. coli promoter than the ORF4 promoter.
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Published date: 2003
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Local EPrints ID: 465154
URI: http://eprints.soton.ac.uk/id/eprint/465154
PURE UUID: 3d5057d5-0184-430b-b8f6-a7b1bf0f7142
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Date deposited: 05 Jul 2022 00:26
Last modified: 16 Mar 2024 19:59
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Author:
Sarah Ann Garner
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