title: Nonmyristoylated matrix protein from the Mason-Pfizer monkey virus forms oligomers.
abstract: We studied the oligomeric properties of betaretroviral nonmyristoylated matrix protein (MA) and its R55F mutant from the Mason-Pfizer monkey virus in solution by means of chemical crosslinking and NMR spectroscopy. By analyzing crosslinked products and using concentration-dependent NMR chemical shift mapping, we have proven that the wild-type (WT) MA forms oligomers in solution. Conversely, no oligomerization was observed for the R55F mutant. Structural comparison of MAs explained their different behaviors in solution, concluding that the key residues involved in intermonomeric interaction are exposed in the WT MA but buried in the mutant, preventing the oligomerization of R55F. The final model of oligomerization of the WT MA was derived by concerted use of chemical shift mapping and diffusion-ordered spectroscopy measured on a set of protein samples with varying concentrations. We found that the Mason-Pfizer monkey virus WT MA exists in a monomer-dimer-trimer equilibrium in solution, with the corresponding dissociation constants of 2.3 and 0.24 mM, respectively. Structures of the oligomers calculated with HADDOCK software are closely related to the structures of other retroviral MA trimers.
authors.affiliation: Institute of Chemical Technology, Prague, Czech Republic.
authors.forename: Jirí
authors.initials: J
authors.lastname: Vlach
authors.forename: Pavel
authors.initials: P
authors.lastname: Srb
authors.forename: Jan
authors.initials: J
authors.lastname: Prchal
authors.forename: Marián
authors.initials: M
authors.lastname: Grocký
authors.forename: Jan
authors.initials: J
authors.lastname: Lang
authors.forename: Tomás
authors.initials: T
authors.lastname: Ruml
authors.forename: Richard
authors.initials: R
authors.lastname: Hrabal
mesh_terms: D000595:Amino Acid Sequence; D003432:Cross-Linking Reagents / Q000494:pharmacology; D004058:Diffusion; D004591:Electrophoresis, Polyacrylamide Gel; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D016093:Mason-Pfizer monkey virus / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry; D019814:Myristic Acid / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D055503:Protein Multimerization / Q000187:drug effects; D020836:Protein Structure, Quaternary; D016415:Sequence Alignment; D014763:Viral Matrix Proteins / Q000737:chemistry*
chemical_list: D003432:Cross-Linking Reagents; D050505:Mutant Proteins; D014763:Viral Matrix Proteins; D019814:Myristic Acid