Structural and energetic basis of infection by the filamentous bacteriophage IKe.
Mol Microbiol
; 84(6): 1124-38, 2012 Jun.
Article
em En
| MEDLINE
| ID: mdl-22591114
ABSTRACT
Filamentous phage use the two N-terminal domains of their gene-3-proteins to initiate infection of Escherichia coli. One domain interacts with a pilus, and then the other domain binds to TolA at the cell surface. In phage fd, these two domains are tightly associated with each other, which renders the phage robust but non-infectious, because the TolA binding site is inaccessible. Activation for infection requires partial unfolding, domain disassembly and prolyl isomerization. Phage IKe infects E. coli less efficiently than phage fd. Unlike in phage fd, the pilus- and TolA-binding domains of phage IKe are independent of each other in stability and folding. The site for TolA binding is thus always accessible, but the affinity is very low. The structures of the two domains, analysed by X-ray crystallography and by NMR spectroscopy, revealed a unique fold for the N-pilus-binding domain and a conserved fold for the TolA-binding domain. The absence of an activation mechanism as in phage fd and the low affinity for TolA probably explain the low infectivity of phage IKe. They also explain why, in a previous co-evolution experiment with a mixture of phage fd and phage IKe, all hybrid phage adopted the superior infection mechanism of phage fd.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Virais
/
Bacteriófago IKe
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Escherichia coli
/
Internalização do Vírus
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2012
Tipo de documento:
Article
País de afiliação:
Alemanha
País de publicação:
ENGLAND
/
ESCOCIA
/
GB
/
GREAT BRITAIN
/
INGLATERRA
/
REINO UNIDO
/
SCOTLAND
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UK
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UNITED KINGDOM