Visualization of the externalized VP2 N termini of infectious human parvovirus B19.
The structures of infectious human parvovirus B19 and empty wild-type particles were determined by cryoelectron microscopy (cryoEM) to 7.5-A and 11.3-A resolution, respectively, assuming icosahedral symmetry. Both of these, DNA filled and empty, wild-type particles contain a few copies of the minor capsid protein VP1. Comparison of wild-type B19 with the crystal structure and cryoEM reconstruction of recombinant B19 particles consisting of only the major capsid protein VP2 showed structural differences in the vicinity of the icosahedral fivefold axes. Although the unique N-terminal region of VP1 could not be visualized in the icosahedrally averaged maps, the N terminus of VP2 was shown to be exposed on the viral surface adjacent to the fivefold beta-cylinder. The conserved glycine-rich region is positioned between two neighboring, fivefold-symmetrically related VP subunits and not in the fivefold channel as observed for other parvoviruses.
Department of Biological Sciences, Purdue University, 915 West State Street, West Lafayette, IN 47907-2054, USA.
Bärbel
B
Kaufmann
Paul R
PR
Chipman
Victor A
VA
Kostyuchenko
Susanne
S
Modrow
Michael G
MG
Rossmann
D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics; D020285:Cryoelectron Microscopy; D006801:Humans; D008958:Models, Molecular; D016732:Parvovirus B19, Human / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure*; D011487:Protein Conformation; D014771:Virion / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure*
D036022:Capsid Proteins; C095547:capsid protein VP1, parvovirus B19; C095548:capsid protein VP2, parvovirus B19