RNA molecules face difficulties when folding into their native structures. In the cell, proteins can assist RNAs in reaching their functionally active states by binding and stabilizing a specific structure or, in a quite opposite way, by interacting in a non-specific manner. These proteins can either facilitate RNA-RNA interactions in a reaction termed RNA annealing, or they can resolve non-fun...

The polyhedrin gene (polh) of Helicoverpa zea single nucleocapsid nuclear polyhedrosis virus (HzSNPV) was identified and shown by sequence analysis of the EcoRI I genomic fragment to encode a 246 amino acid polypeptide that has greater than 80% sequence identity to known polyhedrins. It is preceded by an AT-rich region containing the conserved late promoter motif TAAG, which was identified as a...

Autographa californica nuclear polyhedrosis virus (AcNPV) was used as an expression vector for the nucleocapsid protein gene of Hantaan virus. Two different cDNA clones representing the small genome segment of Hantaan virus were inserted into the transfer vector pAcYM1, and recombinants were generated by replacement of a portion of the baculovirus polyhedrin gene with the foreign, Hantaan virus...

Mouse hepatitis virus (MHV) belongs to the group II coronaviruses. The virus produces nine genes encoding 11 proteins that could be recognized as structural proteins and nonstructural proteins and are crucial for viral RNA synthesis. The nucleocapsid (N) protein, one of the structural proteins, interacts with the 30.4 kb virus genomic RNA to form the helical nucleocapsid and associates with the...

The polyhedral inclusion body of the cotton bollworm nuclear polyhedrosis virus contains virions occluded in an orthogonal crystalline matrix. The virions appear as rods or, more frequently, as oval structures that form upon bending of the nucleocapsid within the viral membrane. The nucleocapsid consists at least of DNA surrounded by a capsid composed of subunits, possibly helically arranged. T...

We report the development of an enzyme-linked immunosorbent assay (ELISA) for the detection of severe acute respiratory syndrome (SARS) coronavirus (CoV) nucleocapsid protein. The assay was carried out with hyperimmune polyclonal nucleocapsid-specific antibodies from guinea pigs and rabbits immunized with recombinant His(6)-tagged SARS CoV nucleocapsid protein. The assay was used for the detect...

Replication of measles virus in HeLa cells was examined by electron microscopy with ultrathin sectioning and phosphotungstic acid negative staining methods. The cytoplasmic inclusion bodies consisted of masses of helical nucleocapsid which was similar in structure to the nucleocapsid found in measles virions. The cytoplasmic helical nucleocapsid appeared to align near the HeLa cell membrane, an...

Alphaviruses are a group of icosahedral, positive-strand RNA, enveloped viruses. The membrane bilayer, which surrounds the approximately 400 A diameter nucleocapsid, is penetrated by 80 spikes arranged in a T = 4 lattice. Each spike is a trimer of heterodimers consisting of glycoproteins E1 and E2. Cryoelectron microscopy and image reconstruction of Ross River virus showed that the T = 4 quater...

Helical nucleocapsids of each of the paramyxoviruses simian virus 5 (SV5), Newcastle disease virus (NDV), and Sendai virus have been isolated in two different forms. One form contains larger protein subunits and is obtained from mature virions or infected cells dispersed by ethylenediaminetetraacetic acid. The other form possesses smaller subunits and is obtained from infected cells dispersed b...