title: Spatial structure peculiarities of influenza A virus matrix M1 protein in an acidic solution that simulates the internal lysosomal medium.
abstract: The structure of the C-terminal domain of the influenza virus A matrix M1 protein, for which X-ray diffraction data were still missing, was studied in acidic solution. Matrix M1 protein was bombarded with thermally-activated tritium atoms, and the resulting intramolecular distribution of the tritium label was analyzed to assess the steric accessibility of the amino acid residues in this protein. This technique revealed that interdomain loops and the C-terminal domain of the protein are the most accessible to labeling with tritium atoms. A model of the spatial arrangement of the C-terminal domain of matrix M1 protein was generated using rosetta software adjusted to the data obtained by tritium planigraphy experiments. This model suggests that the C-terminal domain is an almost flat layer with a three-α-helical structure. To explain the high level of tritium label incorporation into the C-terminal domain of the M1 protein in an acidic solution, we also used independent experimental approaches (CD spectroscopy, limited proteolysis and MALDI-TOF MS analysis of the proteolysis products, dynamic light scattering and analytical ultracentrifugation), as well as multiple computational algorithms, to analyse the intrinsic protein disorder. Taken together, the results obtained in the present study indicate that the C-terminal domain is weakly structured. We hypothesize that the specific 3D structural peculiarities of the M1 protein revealed in acidic pH solution allow the protein greater structural flexibility and enable it to interact effectively with the components of the host cell.
authors: N N Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia.
authors: Alexander
authors: A
authors: Shishkov
authors: Elena
authors: E
authors: Bogacheva
authors: Natalia
authors: N
authors: Fedorova
authors: Alexander
authors: A
authors: Ksenofontov
authors: Gennadii
authors: G
authors: Badun
authors: Victor
authors: V
authors: Radyukhin
authors: Elena
authors: E
authors: Lukashina
authors: Marina
authors: M
authors: Serebryakova
authors: Alexey
authors: A
authors: Dolgov
authors: Alexey
authors: A
authors: Chulichkov
authors: Evgeny
authors: E
authors: Dobrov
authors: Lyudmila
authors: L
authors: Baratova
mesh_terms: D000143:Acids / Q000494:pharmacology; D003198:Computer Simulation; D006863:Hydrogen-Ion Concentration; D053118:Influenza A Virus, H1N1 Subtype / Q000737:chemistry; D007553:Isotope Labeling; D008247:Lysosomes; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D059748:Proteolysis; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014316:Tritium; D014763:Viral Matrix Proteins / Q000737:chemistry*
chemical_list: D000143:Acids; C488936:M1 protein, Influenza A virus; D014763:Viral Matrix Proteins; D014316:Tritium