Genome and proteome analysis of 7-7-1, a flagellotropic phage infecting Agrobacterium sp H13-3.
BACKGROUND
The flagellotropic phage 7-7-1 infects motile cells of Agrobacterium sp H13-3 by attaching to and traveling along the rotating flagellar filament to the secondary receptor at the base, where it injects its DNA into the host cell. Here we describe the complete genomic sequence of 69,391 base pairs of this unusual bacteriophage.


METHODS
The sequence of the 7-7-1 genome was determined by pyro(454)sequencing to a coverage of 378-fold. It was annotated using MyRAST and a variety of internet resources. The structural proteome was analyzed by SDS-PAGE coupled electrospray ionization-tandem mass spectrometry (MS/MS).


RESULTS
Sequence annotation and a structural proteome analysis revealed 127 open reading frames, 84 of which are unique. In six cases 7-7-1 proteins showed sequence similarity to proteins from the virulent Burkholderia myovirus BcepB1A. Unique features of the 7-7-1 genome are the physical separation of the genes encoding the small (orf100) and large (orf112) subunits of the DNA packaging complex and the apparent lack of a holin-lysin cassette. Proteomic analysis revealed the presence of 24 structural proteins, five of which were identified as baseplate (orf7), putative tail fibre (orf102), portal (orf113), major capsid (orf115) and tail sheath (orf126) proteins. In the latter case, the N-terminus was removed during capsid maturation, probably by a putative prohead protease (orf114).
Laboratory for Foodborne Zoonoses, Public Health Agency of Canada, Guelph, ON, NIG 3W4, Canada. kropinsk@queensu.ca
Andrew M
AM
Kropinski
An
A
Van den Bossche
Rob
R
Lavigne
Jean-Paul
JP
Noben
Patrick
P
Babinger
Rüdiger
R
Schmitt
D060054:Agrobacterium / Q000821:virology*; D001435:Bacteriophages / Q000235:genetics* / Q000302:isolation & purification; D004267:DNA Viruses / Q000235:genetics / Q000302:isolation & purification; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics*; D023061:Gene Order; D016679:Genome, Viral; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D020543:Proteome / Q000032:analysis*; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000032:analysis*; D014771:Virion / Q000648:ultrastructure
D004279:DNA, Viral; D020543:Proteome; D014764:Viral Proteins