Tritium planigraphy study of structural alterations in the coat protein of Potato virus X induced by binding of its triple gene block 1 protein to virions.
Alterations in Potato virus X (PVX) coat protein structure after binding of the protein, encoded by the first gene of PVX triple gene block (triple gene block 1 protein, TGBp1), to the virions were studied using tritium planigraphy. Previously, it has been shown that TGBp1 molecules interact with the PVX particle end, containing the 5'-terminus of PVX RNA, and that this interaction results in a strong decrease in virion stability and its transformation to a translationally active state. In this work, it has been shown that the interaction of TGBp1 with PVX virions leads to an increase of approximately 50% in tritium label incorporation into the 176-198 segment of the 236-residue-long PVX coat protein subunit, with some decrease in label incorporation into the N-terminal coat protein region. According to the new 'sandwich' variant of our recently proposed model of the three-dimensional structure of the intravirus PVX coat protein, the 176-198 segment is assigned to the beta-sheet region located at the subunit surface, presumably participating in coat protein interactions with the intravirus RNA and/or in protein-protein interactions, whereas the N-terminal coat protein region corresponds to the other part of the same beta-sheet. For the remaining segments of the PVX coat protein subunit, no significant difference between tritium incorporation into untreated and TGBp1-treated PVX was observed. A detailed description of the 'sandwich' version of the intravirus PVX coat protein model is presented.
A.N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russia.
Elena
E
Lukashina
Gennady
G
Badun
Natalia
N
Fedorova
Alexander
A
Ksenofontov
Maria
M
Nemykh
Marina
M
Serebryakova
Anna
A
Mukhamedzhanova
Olga
O
Karpova
Nina
N
Rodionova
Lyudmila
L
Baratova
Evgeny
E
Dobrov
D036022:Capsid Proteins / Q000737:chemistry* / Q000378:metabolism*; D008958:Models, Molecular; D017863:Potexvirus / Q000737:chemistry; D021122:Protein Subunits / Q000737:chemistry / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000378:metabolism; D014316:Tritium; D014764:Viral Proteins / Q000737:chemistry* / Q000378:metabolism*; D014771:Virion / Q000378:metabolism*
D036022:Capsid Proteins; D021122:Protein Subunits; D012367:RNA, Viral; D014764:Viral Proteins; C058750:coat protein, Potato virus X; D014316:Tritium