DNA packaging and developmental intermediates of a broad host range Vibrio vulnificus bacteriophage 71A-6.
The structural intermediates in the capsid assembly and DNA packaging pathway of Vibrio vulnificus bacteriophage 71A-6, a rod-shaped double-stranded DNA podovirus, were isolated by ultracentrifugation and studied by electron microscopy, SDS-PAGE and pulsed-field gel electrophoretic analysis. Bacteriophage 71A-6 synthesized rod-shaped capsids (mean length=200+/-8 nm; mean width=47+/-3 nm n=50) during its development. Several host proteins that probably help in the assembly and maturation of the capsids were attached to these capsids as spherical structures. A capsid-DNA or DNA packaging complex that consisted of the mature capsids, DNA and a 42.5-kDa protein was also isolated. The size of the capsids increased in length and decreased in width (mean length=220+/-8 nm; mean width=45+/-3 nm n=50) either during or after the DNA packaging. The capsid fractions contained about 12 phage structural proteins and eight host proteins. At least three proteins were tentatively identified: a 38.5-kDa major capsid protein, a 35.2-kDa tail protein and 42.5-kDa packaging initiator or terminator protein. The size of the bacteriophage 71A-6 genome was determined to be 143.0-kb by pulsed-field gel electrophoresis. The total mass of all the mature phage proteins corresponded to only 14.0% of the coding capacity of phage genome.
Khan
S A
SA
Division of Microbiology, National Center for Toxicological Research, Food and Drug Administration, 3900 NCTR Road, Jefferson, AR 72079, USA.
Khan
A A
AA
Nawaz
M S
MS
DePaola
A
A
Andrews
A
A
Cerniglia
C E
CE
D001435:Bacteriophages / Q000235:genetics* / Q000302:isolation & purification / Q000648:ultrastructure; D002213:Capsid / Q000737:chemistry* / Q000648:ultrastructure; D004279:DNA, Viral; D016521:Electrophoresis, Gel, Pulsed-Field; D004591:Electrophoresis, Polyacrylamide Gel; D008854:Microscopy, Electron; D014733:Vibrio / Q000821:virology*; D017376:Viral Tail Proteins / Q000737:chemistry / Q000648:ultrastructure; D019065:Virus Assembly
D004279:DNA, Viral; D017376:Viral Tail Proteins