Origin and function of the two major tail proteins of bacteriophage SPP1.
The majority of bacteriophages have a long non-contractile tail (Siphoviridae) that serves as a conduit for viral DNA traffic from the phage capsid to the host cell at the beginning of infection. The 160-nm-long tail tube of Bacillus subtilis bacteriophage SPP1 is shown to be composed of two major tail proteins (MTPs), gp17.1 and gp17.1*, at a ratio of about 3:1. They share a common amino-terminus, but the latter species has approximately 10 kDa more than gp17.1. A CCC.UAA sequence with overlapping proline codons at the 3' end of gene 17.1 drives a programmed translational frameshift to another open reading frame. The recoding event generates gp17.1*. Phages carrying exclusively gp17.1 or gp17.1* are viable, but tails are structurally distinct. gp17.1 and the carboxyl-terminus of gp17.1* have a distinct evolutionary history correlating with different functions: the polypeptide sequence identical in the two proteins is responsible for assembly of the tail tube while the additional module of gp17.1* shields the structure exterior exposed to the environment. The carboxyl-terminal extension is an elaboration present in some tailed bacteriophages. Different extensions were found to combine in a mosaic fashion with the MTP essential module in a subset of Siphoviridae genomes.
Auzat
Isabelle
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Unité de Virologie Moléculaire et Structurale, CNRS UMR 2472, INRA UMR1157 and IFR 115, Bâtiment 14B, CNRS, 91198 Gif-sur-Yvette, France.
Dröge
Anja
A
Weise
Frank
F
Lurz
Rudi
R
Tavares
Paulo
P
D017103:Bacillus Phages / Q000235:genetics* / Q000502:physiology; D001412:Bacillus subtilis / Q000821:virology; D004279:DNA, Viral / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics; D019143:Evolution, Molecular; D018965:Frameshifting, Ribosomal; D005814:Genes, Viral; D016679:Genome, Viral; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D010957:Plasmids; D017386:Sequence Homology, Amino Acid; D017376:Viral Tail Proteins / Q000235:genetics*; D014779:Virus Replication / Q000235:genetics
D004279:DNA, Viral; D017376:Viral Tail Proteins