Size and position of truncations in the carboxy-terminal region of major capsid protein VP1 of hamster polyomavirus expressed in yeast determine its assembly capacity.
The hamster polyomavirus major capsid protein VP1 was modified in its carboxy-terminal region by consecutive truncations and single amino acid exchanges. The ability of yeast-expressed VP1 variants to form virus-like particles (VLPs) strongly depended on the size and position of the truncation. VP1 variants lacking 21, 69, and 79 amino acid (aa) residues in their carboxy-terminal region efficiently formed VLPs similar to those formed by the unmodified VP1 (diameter 40-45 nm). In contrast, VP1 derivatives with carboxy-terminal truncations of 35 to 56 aa residues failed to form VLPs. VP1 mutants with a single A336G aa exchange or internal deletions of aa 335 to aa 346 and aa 335 to aa 363 resulted in the formation of VLPs of a smaller size (diameter 20 nm). These data indicate that certain parts of the carboxy-terminal region of VP1 are not essential for pentamer-pentamer interactions in the capsid, at least in the yeast expression system used.
Gedvilaite
A
A
Institute of Biotechnology, Vilnius, Lithuania. agedv@ibt.lt
Aleksaite
E
E
Staniulis
J
J
Ulrich
R
R
Sasnauskas
K
K
D000595:Amino Acid Sequence; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018389:Codon, Nonsense; D004591:Electrophoresis, Polyacrylamide Gel; D046529:Microscopy, Electron, Transmission; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D011120:Polyomavirus / Q000235:genetics* / Q000502:physiology*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics; D017384:Sequence Deletion; D022701:Virosomes / Q000378:metabolism* / Q000648:ultrastructure; D019065:Virus Assembly
D036022:Capsid Proteins; D018389:Codon, Nonsense; D011994:Recombinant Proteins; C062481:VP1 protein, polyomavirus; D022701:Virosomes