Identification of amino acid residues within simian virus 40 capsid proteins Vp1, Vp2, and Vp3 that are required for their interaction and for viral infection.
Interaction of simian virus 40 (SV40) major capsid protein Vp1 with the minor capsid proteins Vp2 and Vp3 is an integral aspect of the SV40 architecture. Two Vp3 sequence elements mediate Vp1 pentamer binding in vitro, Vp3 residues 155 to 190, or D1, and Vp3 residues 222 to 234, or D2. Of the two, D1 but not D2 was necessary and sufficient to direct the interaction with Vp1 in vivo. Rational mutagenesis of Vp3 residues (Phe157, Ile158, Pro164, Gly165, Gly166, Leu177, and Leu181) or Vp1 residues (Val243 and Leu245), based on a structural model of the SV40 Vp1 pentamer complexed with Vp3 D1, was carried out to disrupt the interaction between Vp1 and Vp3 and to study the consequences of these mutations for viral viability. Altering these residues to bulky, charged residues blocked the interaction in vitro. When these alterations were introduced into the viral genome, they reduced viral viability. Mutants with alterations in Vp1 Val243, Leu245, or both to glutamate were nearly nonviable, whereas those with Vp3 alterations reduced, but did not eliminate, viability. Our results defined the residues of Vp1 and the minor capsid proteins that are essential for both the interaction of the capsid proteins and viral viability in permissive cells.
Nakanishi
Akira
A
Molecular Biology Institute, University of California-Los Angeles, 611 East Charles E. Young Drive, Los Angeles, CA 90095-1570, USA.
Nakamura
Akiko
A
Liddington
Robert
R
Kasamatsu
Harumi
H
D000818:Animals; D036022:Capsid Proteins / Q000737:chemistry* / Q000235:genetics; D002460:Cell Line; D002522:Chlorocebus aethiops; D006801:Humans; D009154:Mutation; D027601:Polyomavirus Infections / Q000821:virology*; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D014412:Tumor Virus Infections / Q000821:virology
D036022:Capsid Proteins; D011994:Recombinant Proteins; C062481:VP1 protein, polyomavirus; C085902:VP3 protein, Simian virus 40; C514199:Vp2 protein, simian virus 40