Bacteriophage T4 host range is expanded by duplications of a small domain of the tail fiber adhesin.
The adsorption specificity of T4 is determined by the tip of the gene 37 tail fibers which bind to receptors on the bacterial surface. T4 infects only Escherichia coli and closely related Shigella species, but rare host range mutants can be isolated that infect Yersinia pseudotuberculosis I, an evolutionally distant bacterium. Some of these mutations result in amino acid residue substitutions in the C-terminal portion of gene 37, but others involve unequal exchanges between a series of sequence motifs (His boxes) in the same region. The duplication or mutational alteration of this segment apparently suffices for phage adsorption to a Yersinia receptor. It is suggested that recombination between the His box sequences can generate diversity in phage host range by shuffling receptor recognition domains.
Tétart
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Laboratoire de Microbiologie et Génétique Moléculaire CNRS, Toulouse, France.
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Monod
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Krisch
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D000327:Adsorption; D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000235:genetics / Q000502:physiology*; D010582:Bacteriophage lambda / Q000737:chemistry; D001483:Base Sequence; D004926:Escherichia coli / Q000821:virology*; D008969:Molecular Sequence Data; D005810:Multigene Family; D011991:Receptors, Virus / Q000378:metabolism; D011995:Recombination, Genetic; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012760:Shigella / Q000821:virology*; D017376:Viral Tail Proteins / Q000235:genetics / Q000502:physiology*; D015011:Yersinia pseudotuberculosis / Q000821:virology*
D011991:Receptors, Virus; D017376:Viral Tail Proteins; C099542:gene 37 protein, Enterobacteria phage T4