Horizontal transfer of mobile genetic elements within Staphylococci is of high biomedical significance as such elements are frequently responsible for virulence and toxic effects. Staphylococcus-encoded repressor proteins regulate the replication of these mobile genetic elements that are located within the so-called pathogenicity islands. Here, we report structural and functional characterizati...

High replicative fitness is a general determinant of a multidrug resistance phenotype and may explain lower sensitivity to direct-acting antiviral agents (DAAs) in some hepatitis C virus genotypes. Genetic diversity in the molecular target site of peptidomimetic NS3 protease inhibitors could impact variant replicative fitness and potentially add to virologic treatment failure. We selected NS3 h...

Caspases have several allosteric sites that bind small molecules or peptides. Allosteric regulators are known to affect caspase enzyme activity, in general, by facilitating large conformational changes that convert the active enzyme to a zymogen-like form in which the substrate-binding pocket is disordered. Mutations in presumed allosteric networks also decrease activity, although large structu...

Antifreeze proteins (AFPs) enhance the survival of organisms inhabiting cold environments by affecting the formation and/or structure of ice. We report the crystal structure of the first multi-domain AFP that has been characterized. The two ice binding domains are structurally similar. Each consists of an irregular β-helix with a triangular cross-section and a long α-helix that runs parallel on...

We recently reported a beta-peptide foldamer, beta53-1, that folds into a 14-helix in aqueous solution, binds the oncoprotein hDM2 with submicromolar affinity, and potently inhibits the interaction of hDM2 with a peptide derived from the activation domain of p53 (p53AD). Here, we present the solution structure of beta53-1 in methanol. Details of the structure illustrate fundamental and novel el...

The concept that the structure of the ribosome determines its function is simple. In practice, linking the two is not. Toward this general goal, we have undertaken an integrated approach employing the methods of molecular genetics, biochemistry, structural biology and molecular modeling in the model eukaryotic organism, Saccharomyces cerevisae. Both selected ribosomal proteins and rRNA residues...

The twisting deformation of mechanically stretched DNA molecules is studied by a coarse grained Hamiltonian model incorporating the fundamental interactions that stabilize the double helix and accounting for the radial and angular base pair fluctuations. The latter are all the more important at short length scales in which DNA fragments maintain an intrinsic flexibility. The presented computati...

In the presence of Rashba-Dresselhaus coupling, strong spin-orbit interactions in liquid-crystal optical cavities result a distinctive spin-split entangled dispersion. Spin coherence between such modes gives rise to an optically persistent spin helix. this paper, we introduce gain system, by dispersing molecular dye microcavity, and demonstrate spin-helix lasing regime.

The ultrafast folding pathway of the engrailed homeodomain has been exceptionally well characterized by experiment and simulation. Helices II and III of the three-helix bundle protein form the native helix-turn-helix motif as an on-pathway intermediate within a few microseconds. The slow step is then the proper docking of the helices in approximately 15 mus. However, there is still the unexplai...