title: The structure of an infectious P22 virion shows the signal for headful DNA packaging.
abstract: Bacteriophages, herpesviruses, and other large double-stranded DNA (dsDNA) viruses contain molecular machines that pump DNA into preassembled procapsids, generating internal capsid pressures exceeding, by 10-fold, that of bottled champagne. A 17 angstrom resolution asymmetric reconstruction of the infectious P22 virion reveals that tightly spooled DNA about the portal dodecamer forces a conformation that is significantly different from that observed in isolated portals assembled from ectopically expressed protein. We propose that the tight dsDNA spooling activates the switch that signals the headful chromosome packing density to the particle exterior.
authors.affiliation: Department of Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
authors.forename: Gabriel C
authors.initials: GC
authors.lastname: Lander
authors.forename: Liang
authors.initials: L
authors.lastname: Tang
authors.forename: Sherwood R
authors.initials: SR
authors.lastname: Casjens
authors.forename: Eddie B
authors.initials: EB
authors.lastname: Gilcrease
authors.forename: Peter
authors.initials: P
authors.lastname: Prevelige
authors.forename: Anton
authors.initials: A
authors.lastname: Poliakov
authors.forename: Clinton S
authors.initials: CS
authors.lastname: Potter
authors.forename: Bridget
authors.initials: B
authors.lastname: Carragher
authors.forename: John E
authors.initials: JE
authors.lastname: Johnson
mesh_terms: D017100:Bacteriophage P22 / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure*; D002213:Capsid / Q000737:chemistry / Q000648:ultrastructure*; D036022:Capsid Proteins / Q000737:chemistry; D020285:Cryoelectron Microscopy; D018360:Crystallography, X-Ray; D042003:DNA Packaging; D004279:DNA, Viral / Q000032:analysis* / Q000737:chemistry; D007091:Image Processing, Computer-Assisted; D009690:Nucleic Acid Conformation; D011312:Pressure; D011487:Protein Conformation; D014771:Virion / Q000235:genetics / Q000648:ultrastructure*
chemical_list: D036022:Capsid Proteins; D004279:DNA, Viral