Oligomerization of the Potato Virus X 25-kD Movement Protein

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A. D. Leshchiner^1,2, E. A. Minina³, D. V. Rakitina¹, V. K. Vishnichenko², A. G. Solovyev^1,2, S. Yu. Morozov¹, and N. O. Kalinina^1*

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia; fax: (495) 939-3181; E-mail: kalinina@genebee.msu.ru

²Institute of Agricultural Biotechnology, Russian Academy of Agricultural Sciences, ul. Timiryazevskaya 42, 127550 Moscow, Russia; fax: (495) 977-0947; E-mail: vish@iab.ac.ru

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: alyona.minina@gmail.com

^* To whom correspondence should be addressed.

Received June 21, 2007

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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.

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KEY WORDS: potato virus X, movement protein, oligomerization, yeast two-hybrid system, glutaraldehyde

DOI: 10.1134/S0006297908010070

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