STRUCTURAL COMPARISON OF WILD-TYPE MATRIX PROTEIN FROM M-PMV AND ITS R55F MUTANT

J. Vlach¹, V. Veverka¹, J. Lipov², P. Srb³, J. Lang^1,3, T. Ruml² and R. Hrabal¹

¹Laboratory of NMR Spectroscopy,

²Department of Biochemistry and Microbiology, Institute of Chemical Technology, Technická 5, 166 28 Prague 6, Czech Republic

³Department of Low Temperature Physics, Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 182 02 Prague 8, Czech Republic

Mason-Pfizer monkey virus (M-PMV) belongs to the genus of betaretroviruses which differ from lentiviruses (e. g. HIV-1) in a mechanism of immature capsid assembly. Matrix protein (MA) plays an essential role in different stages of retrovirus maturation. A single point mutation (R55F) in the sequence of the wt MA, however, changes the morphogenesis of the virus and capsids are assembled at the plasma membrane instead of in the cytoplasm, similarly to the lentiviruses.¹

We have focused on the study of three-dimensional structure and dynamics of both proteins (wt MA and R55F mutant) by NMR spectroscopy to reveal possible structural changes caused by the mutation (R55F). Although a structure of the wt MA has already been published as C-alpha trace², we decided to perform a new study of this protein to obtain a complete 3D structure. Doubly labelled (¹³C, ¹⁵N) proteins were prepared using recombinant techniques. Standard triple resonance NMR experiments were used for the assignment of resonances and three-dimensional structures of the proteins were calculated based on NMR parameters (NOE interactions, J- and residual dipolar couplings, etc.). Dynamical behaviour of both proteins was estimated based on ¹⁵N relaxation properties. Comparison of the structure of R55F mutant with wild-type MA will be presented.

Acknowledgement:

We thank the Grant Agency of the Czech Republic for the financial support (Grants 203/03/0490 and 203/04/P168).

1. S.S. Rhee and E. Hunter, Cell, 5 (1990) 77-86.

2. M.R. Conte, M. Kliková, E. Hunter, T. Ruml and S. Matthews, EMBO J., 16 (1997) 5819-5826.