L. Stavolone et al., Tetramerization is a conserved feature of the virion-associated protein inplant pararetroviruses, J VIROLOGY, 75(16), 2001, pp. 7739-7743
All plant pararetroviruses belong to the Caulimoviridae family. This family
contains six genera of viruses with different biological, serological, and
molecular characteristics. Although some important mechanisms of viral rep
lication and host infection are understood, much remains to be discovered a
bout the many functions of the viral proteins. The focus of this study, the
virion-associated protein (VAP), is conserved among all members of the gro
up and contains a coiled-coil structure that has been shown to assemble as
a tetramer in the case of cauliflower mosaic virus. We have used the yeast
two-hybrid system to characterize self-association of the VAPs of four dist
inct plant pararetroviruses, each belonging to a different genus of Caulimo
viridae. Chemical cross-linking confirmed that VAPs assemble into tetramers
. Tetramerization is thus a common property of these proteins in plant para
retroviruses. The possible implications of this conserved feature for VAP f
unction are discussed.