The C-terminal domain of TolA is the coreceptor for filamentous phage infection of E. coli.
Filamentous bacteriophages infecting gram-negative bacteria display tropism for a variety of pilus structures. However, the obligatory coreceptor of phage infection, postulated from genetic studies, has remained elusive. Here we identify the C-terminal domain of the periplasmic protein TolA as the coreceptor for infection of Escherichia coli by phage fd and the N-terminal domain of the phage minor coat protein g3p as its cognate ligand. The neighboring g3p domain binds the primary receptor of phage infection, the F pilus, and blocks TolA binding in its absence. Contact with the pilus releases this blockage during infection. Our findings support a sequential two-way docking mechanism for phage infection, analogous to infection pathways proposed for a range of eukaryotic viruses including herpes simplex, adenoviruses, and also lentiviruses like HIV-1.
Riechmann
L
L
MRC Laboratory of Molecular Biology, Cambridge, United Kingdom.
Holliger
P
P
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017104:Bacteriophage M13 / Q000737:chemistry / Q000378:metabolism*; D036022:Capsid Proteins; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D004926:Escherichia coli / Q000737:chemistry / Q000821:virology*; D029968:Escherichia coli Proteins; D010861:Fimbriae, Bacterial / Q000378:metabolism / Q000821:virology; D017353:Gene Deletion; D017912:Inovirus / Q000737:chemistry / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis / Q000502:physiology; D011485:Protein Binding / Q000502:physiology; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D036022:Capsid Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D011994:Recombinant Proteins; D014760:Viral Fusion Proteins; C062093:tolA protein, E coli