title: NMR structure of the N-terminal domain of capsid protein from the mason-pfizer monkey virus.
abstract: The high-resolution structure of the N-terminal domain (NTD) of the retroviral capsid protein (CA) of Mason-Pfizer monkey virus (M-PMV), a member of the betaretrovirus family, has been determined by NMR. The M-PMV NTD CA structure is similar to the other retroviral capsid structures and is characterized by a six alpha-helix bundle and an N-terminal beta-hairpin, stabilized by an interaction of highly conserved residues, Pro1 and Asp57. Since the role of the beta-hairpin has been shown to be critical for formation of infectious viral core, we also investigated the functional role of M-PMV beta-hairpin in two mutants (i.e., DeltaP1NTDCA and D57ANTDCA) where the salt bridge stabilizing the wild-type structure was disrupted. NMR data obtained for these mutants were compared with those obtained for the wild type. The main structural changes were observed within the beta-hairpin structure; within helices 2, 3, and 5; and in the loop connecting helices 2 and 3. This observation is supported by biochemical data showing different cleavage patterns of the wild-type and the mutated capsid-nucleocapsid fusion protein (CANC) by M-PMV protease. Despite these structural changes, the mutants with disrupted salt bridge are still able to assemble into immature, spherical particles. This confirms that the mutual interaction and topology within the beta-hairpin and helix 3 might correlate with the changes in interaction between immature and mature lattices.
authors.affiliation: National Centre for Biomolecular Research, Masaryk University, Kotlárská, Brno, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Macek
authors.forename: Josef
authors.initials: J
authors.lastname: Chmelík
authors.forename: Ivana
authors.initials: I
authors.lastname: Krízová
authors.forename: Pavel
authors.initials: P
authors.lastname: Kaderávek
authors.forename: Petr
authors.initials: P
authors.lastname: Padrta
authors.forename: Lukás
authors.initials: L
authors.lastname: Zídek
authors.forename: Marcela
authors.initials: M
authors.lastname: Wildová
authors.forename: Romana
authors.initials: R
authors.lastname: Hadravová
authors.forename: Radka
authors.initials: R
authors.lastname: Chaloupková
authors.forename: Iva
authors.initials: I
authors.lastname: Pichová
authors.forename: Tomás
authors.initials: T
authors.lastname: Ruml
authors.forename: Michaela
authors.initials: M
authors.lastname: Rumlová
authors.forename: Vladimír
authors.initials: V
authors.lastname: Sklenár
mesh_terms: D019943:Amino Acid Substitution; D036022:Capsid Proteins / Q000737:chemistry*; D016093:Mason-Pfizer monkey virus / Q000737:chemistry*; D008958:Models, Molecular; D050505:Mutant Proteins / Q000737:chemistry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D017434:Protein Structure, Tertiary; D017384:Sequence Deletion
chemical_list: D036022:Capsid Proteins; D050505:Mutant Proteins