Transfer of R388 derivatives by a pathogenesis-associated type IV secretion system into both bacteria and human cells.
J Bacteriol
; 193(22): 6257-65, 2011 Nov.
Article
em En
| MEDLINE
| ID: mdl-21908662
ABSTRACT
Bacterial type IV secretion systems (T4SSs) are involved in processes such as bacterial conjugation and protein translocation to animal cells. In this work, we have switched the substrates of T4SSs involved in pathogenicity for DNA transfer. Plasmids containing part of the conjugative machinery of plasmid R388 were transferred by the T4SS of human facultative intracellular pathogen Bartonella henselae to both recipient bacteria and human vascular endothelial cells. About 2% of the human cells expressed a green fluorescent protein (GFP) gene from the plasmid. Plasmids of different sizes were transferred with similar efficiencies. B. henselae codes for two T4SSs VirB/VirD4 and Trw. A ΔvirB mutant strain was transfer deficient, while a ΔtrwE mutant was only slightly impaired in DNA transfer. DNA transfer was in all cases dependent on protein TrwC of R388, the conjugative relaxase, implying that it occurs by a conjugation-like mechanism. A DNA helicase-deficient mutant of TrwC could not promote DNA transfer. In the absence of TrwB, the coupling protein of R388, DNA transfer efficiency dropped 1 log. The same low efficiency was obtained with a TrwB point mutation in the region involved in interaction with the T4SS. TrwB interacted with VirB10 in a bacterial two-hybrid assay, suggesting that it may act as the recruiter of the R388 substrate for the VirB/VirD4 T4SS. A TrwB ATPase mutant behaved as dominant negative, dropping DNA transfer efficiency to almost null levels. B. henselae bacteria recovered from infected human cells could transfer the mobilizable plasmid into recipient Escherichia coli under certain conditions, underscoring the versatility of T4SSs.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Plasmídeos
/
Proteínas de Bactérias
/
Transfecção
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Angiomatose Bacilar
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Bartonella henselae
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Conjugação Genética
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Células Endoteliais
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Sistemas de Secreção Bacterianos
Tipo de estudo:
Etiology_studies
/
Risk_factors_studies
Limite:
Humans
Idioma:
En
Ano de publicação:
2011
Tipo de documento:
Article