2Institute of Agricultural Biotechnology, Russian Academy of Agricultural Sciences, ul. Timiryazevskaya 42, 127550 Moscow, Russia; fax: (495) 977-0947; E-mail: email@example.com
3Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, ul. Miklukho-Maklaya 16/10, 117997 Moscow, Russia; fax: (495) 336-4511; E-mail: firstname.lastname@example.org
* To whom correspondence should be addressed.
Received June 21, 2007
A 25-kD movement protein (25K protein) encoded by the first gene of the potexvirus Potato virus X triple gene block of transport genes is essential for the viral movement in infected plants. The 25K protein belongs to superfamily 1 of NTPase/helicases and exhibits in vitro RNA helicase, Mg2+-dependent NTPase, and RNA-binding activities. In the present work, the ability of 25K protein for homologous interactions was studied using the yeast two-hybrid system, protein chemical cross-linking in the presence of glutaraldehyde, far-Western blotting, and ultracentrifugation in sucrose density gradients. The 25K protein was shown to form homodimers and homooligomers. Sites of homologous protein-protein interactions were found in both the N- and C-terminal portions of the protein.
KEY WORDS: potato virus X, movement protein, oligomerization, yeast two-hybrid system, glutaraldehyde