Cold and distant: structural features of the nucleoprotein complex of a cold-adapted influenza A virus strain.

Two influenza A nucleoprotein variants (wild-type: G102R; and mutant: G102R and E292G) were studied with regard to macro-molecular interactions in oligomeric form (24-mers). The E292G mutation has been previously shown to provide cold adaptation. Molecular dynamics simulations of these complexes and trajectory analysis showed that the most significant difference between the obtained models was distance between nucleoprotein complex strands.

Structure of RecX protein complex with the presynaptic RecA filament: Molecular dynamics simulations and small angle neutron scattering.

Using molecular modeling techniques we have built the full atomic structure and performed molecular dynamics simulations for the complexes formed by Escherichia coli RecX protein with a single-stranded oligonucleotide and with RecA presynaptic filament. Based on the modeling and SANS experimental data a sandwich-like filament structure formed two chains of RecX monomers bound to the opposite sides of the single stranded DNA is proposed for RecX::ssDNA complex. The model for RecX::RecA::ssDNA include RecX binding into the grove of RecA::ssDNA filament that occurs mainly via Coulomb interactions between RecX and ssDNA.

[Current insights into chromatin structure organization].

This review summarizes current insights into organization of chromatin structure at different levels of DNA compaction. Analysis of available experimental data allowed concluding that only nucleosomal level of structural organization was sufficiently investigated, whereas structure of a 30-nm chromatin fiber remains an open issue. The data on the chromatin structure obtained at the level of the nucleus speak in favor of a biphasic fractal organization of chromatin.