摘要:

The interrelationship of a number of potyviruses infecting legumes has been investigated by comparing molecular properties of their coat proteins. Comparison of the coat proteins by the techniques of amino acid analysis and PAGE was inadequate to distinguish strains from distinct potyviruses. However, high-performance liquid chromatographic peptide profiles of tryptic digests of coat proteins of these legume-infecting potyviruses enabled such assignments to be made. These data indicate that amino acid sequences of coat proteins of azuki bean mosaic virus, the Type and W strains of blackeye cowpea mosaic virus, three isolates (74, PM, PN) of a potyvirus obtained from soybean in Taiwan, and the Blotch and Mild Mottle strains of peanut stripe virus (PStV) may be very similar to the known sequence of PStV Stripe coat protein. In contrast, peptide profiles of coat proteins from soybean mosaic virus, clover yellow vein virus, bean yellow mosaic virus, potato virus Y, and tobacco etch virus were dissimilar to each other and to the profile of PStV Stripe, suggesting that their coat protein sequences were also quite different. Based on observations of the coat protein structure of many potyviruses, the results suggest that the potyvirus isolates with similar coat proteins are strains of the same potyvirus.

ISSN:0300-5526    

DOI:10.1159/000150241

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Twelve cDNA clones were generated, covering approximately 95% of the cowpea mottle virus (CMeV) genome from the 3’ end to near the 5’ end. The entire capsid protein sequence of 1,104 nucleotides was contained in two clones located near the 3’ terminus. The codons represented 367 amino acids (Mr 39,611). The postulated amino acid sequence of CMeV capsid protein had 36% homology to turnip crinkle virus and 26% homology to carnation mottle virus in the arm and S domains, but western blots showed no serological relationship to either. On the basis of the organization and expression of its genome and its physicochemical properties, CMeV is assigned to the carmovirus group. Like other carmoviruses, CMeV generates three dsRNAs which are co-terminal at the 3’ end in infected tissues, but CMeV differs from other carmoviruses in the absence of encapsidated subgenom

ISSN:0300-5526    

DOI:10.1159/000150242

出版商:S. Karger AG    

年代:1992

数据来源: Karger

ISSN:0300-5526    

DOI:10.1159/000150243

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

A model of hepatitis B surface antigen has been derived, based on extensive sequence analysis and biochemical data. The surface antigen sequences of the human, woodchuck, ground squirrel and duck hepadnaviruses were examined using hydrophobicity, hydrophobic moments, flexibility and secondary structure prediction. The helix phase diagram, which is a modified version of Eisenberg’s hydrophobic moment plots and which specifically addresses the problem of transmembrane helices, was used to examine the predicted helices. In this model four transmembrane helices are predicted. The N and C termini and the second hydrophilic region, which bears the major B-cell antigenic determinants, are external. It is suggested that the transmembrane helices may pack to form a channel through the membrane and may also be involved in the mechanisms of cell entry. A significant difference between the duck hepadnavirus and the mammalian HBsAg sequences was found, hence care must be taken when extrapolating data between the duck and the human surface antige

ISSN:0300-5526    

DOI:10.1159/000150244

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

In situ hybridization, using a biotinylated clone of frog erythrocytic virus (FEV), was conducted to determine the location of viral sequences in bullfrog erythrocytes. FEV-specific hybridization signals were found to correspond to mature cytoplasmic viral particles and assembly sites. These data are consistent with electron microscopic observations of viral assembly in the erythrocyte cytoplasm. Although FEV has morphological and biochemical properties similar to frog virus 3, our data suggest that the site of DNA replication and assembly of FEV is more similar to that of the poxviruses.

ISSN:0300-5526    

DOI:10.1159/000150245

出版商:S. Karger AG    

年代:1992

数据来源: Karger

摘要:

Although mutations in codons 164 and 179 of poliovirus polypeptide 2C can establish guanidine resistance, the majority of guanidine-resistant and guanidine-dependent viruses contain an M → L change at amino residue 187 along with other critical mutations. The change at residue 187 probably contributes to the guanidine phenotype along with a variety of other modifications in polypeptide 2C, possibly altering conformation of the polypeptide during the initiation step of viral RNA synthesi

ISSN:0300-5526    

DOI:10.1159/000150246

出版商:S. Karger AG    

年代:1992

数据来源: Karger