The 3' ends of three genomic RNAs (gRNAs) of cowpea chlorotic mottle virus (CCMV) terminate in a highly conserved tRNA-like structure (3'TLS). To examine the intrinsic role played the 3'TLS in packaging, the competence of each gRNA lacking the 3' TLS (DeltaTLS-gRNA) to interact with dissociated coat protein (CP) subunits and form virions was assayed in vitro. In contrast to the well established...

Our laboratory has previously reported isolation of human rhinovirus type 16 (HRV16) mutants which depend on WIN 52035 to grow. A rapid rise of progeny virus infectivity occurred when drug was added late in growth cycles, suggesting that the drug-dependence lesion was at the step of virus assembly (W. Wang et al., J. Virol. 72:1210-1218, 1998). Here, we report that capsid subunits, 5S protomers...

Our studies on the assembly of hepatitis B virus capsids or core particles in Xenopus oocytes have demonstrated that unassembled p21.5 core proteins ("free p21.5") provide a pool of low-molecular-mass precursors for core-particle assembly. Here we have characterized this material. Free p21.5 sedimented through gradients of 3-25% sucrose (wt/vol) as a single protein species of approximately 40 k...

The modification patterns of histones present in various forms of intracellular simian virus 40 nucleoprotein complexes were analyzed by acetic acid-urea-polyacrylamide gel electrophoresis. The results showed that different viral nucleoprotein complexes contain different histone patterns. Simian virus 40 chromatin, which contains the activities for the synthesis of viral RNA and DNA, exhibits a...

This review addresses the technical problems encountered while using models based on electron microscopy to generate initial phases for crystallographic studies. The test cases used were the gp6 portal protein with 13-fold rotational symmetry and the human hepatitis virus HepB, a viral assembly with T = 4 icosohedral symmetry.

Many viruses exploit cellular polarity to constrain the assembly and release of progeny virions to a desired surface. Influenza virus particles are released only from the apical surface of epithelial cells and this polarization is partly owing to specific targeting of the viral membrane proteins to the apical plasma membrane. The RNA genome of the virus is transcribed and replicated in the nucl...

The nucleocapsid (NC) domain of retroviruses plays a critical role in specific viral RNA packaging and virus assembly. RNA is thought to facilitate viral particle assembly, but the results described here with NC mutants indicate that it also plays a critical role in particle integrity. We investigated the assembly and integrity of particles produced by the human immunodeficiency virus type 1 M1...

To destroy all remaining stocks of variola virus on or before 31 December 2002 seems an even more compelling goal today than it did in 1999, when the 52d World Health Assembly authorized temporary retention of remaining stocks to facilitate the possible development of (1) a more attenuated, less reactogenic smallpox vaccine and (2) an antiviral drug that could be used in treatment of patients w...

The alphaviruses are composed of two icosahedral protein shells, one nested within the other. A membrane bilayer derived from the host cell is sandwiched between the protein shells. The protein shells are attached to one another by protein domains which extend one of the proteins of the outer shell through the membrane bilayer to attach to the inner shell. We have examined the interaction of th...