Summary auto-generated
This 1986 study determined the complete nucleotide sequence of the fusion (F) gene of Newcastle disease virus (NDV) strain Beaudette C from cDNA clones, revealing a 1792-nucleotide gene encoding a 553-amino acid precursor protein (F0) with a predicted molecular weight of 59,042 Da. The F0 glycoprotein contains three hydrophobic regions: an N-terminal signal peptide, the N-terminal region of the cleaved F1 fragment, and a C-terminal membrane-anchoring segment. Five potential asparagine-linked glycosylation sites are present in the sequence, with proteolytic cleavage occurring at a highly basic region to generate the disulfide-linked F1 and F2 fragments required for viral infectivity. Comparison of the NDV F sequence with other paramyxoviruses (Sendai virus, simian virus 5, and respiratory syncytial virus) revealed homology throughout the sequences, with 33% amino acid identity between NDV and simian virus 5 F proteins. Limited homology was also detected between the N-terminus of NDV F1 and influenza virus HA2. The authors discuss post-translational modifications including signal peptide cleavage, glycosylation, fatty acid acylation, and disulfide bond formation in the context of the determined amino acid sequence.
Key findings
- The NDV F gene encodes a 553-amino acid precursor containing three highly hydrophobic regions: an N-terminal signal peptide, the N-terminus of the F1 cleavage product, and a C-terminal membrane-spanning domain
- Five potential asparagine-linked glycosylation sites are present in the F0 sequence, with four in F1 and one in F2, all consistent with high-mannose type glycosylation observed in NDV
- The F glycoprotein amino acid sequence shares homology with other paramyxoviruses (33% identity with simian virus 5) and limited homology with influenza virus HA2, suggesting evolutionary conservation of fusion protein structure
- All ten cysteines between the signal peptide and transmembrane region are conserved among NDV, simian virus 5, and Sendai virus, likely important for disulfide bond formation and conformational changes during biosynthesis
- A cysteine residue near the cytoplasmic face of the transmembrane region may serve as a site for fatty acid acylation of the NDV F protein
This summary was generated automatically from the article PDF and is not part of the original publication. Refer to the PDF for the authoritative text.
Abstract
The nucleotide sequence of the gene encoding the fusion (F) glycoprotein of the Beaudette C strain of Newcastle disease virus (NDV) has been determined from cDNA clones obtained from virion RNA. The gene is 1792 nucleotides long, including mRNA start and polyadenylation signals typical of paramyxoviruses. The single open reading frame encodes a polypeptide of 553 amino acids, with a predicted molecular weight of 59042. The F polypeptide has three regions of high hydrophobicity: an N-terminal signal peptide, the N terminus of F1 (known from protein sequencing) and a C-terminal membrane-spanning region by which the F glycoprotein is anchored to the membrane. The cleavage site of F0 is located in a highly basic region of the F polypeptide. Five potential asparagine-linked glycosylation sites are present in the amino acid sequence, of which one is in F2 and the others in F1. Comparison of the NDV F amino acid sequence to those from other paramyxoviruses reveals homology to Sendai virus, simian virus 5 and human respiratory syncytial virus. There is also limited homology between the N terminus of F1 of NDV and the N termini of HA2 of influenza viruses. Post-translational modifications of the NDV F polypeptide are discussed in the light of information provided by the amino acid sequence.