In bacteria, ribosomal hibernation shuts down translation as a response to stress, through reversible binding of stress-induced proteins to ribosomes. This process typically involves the formation of 100S ribosome dimers. Here, we present the structures of hibernating ribosomes from human pathogen Staphylococcus aureus containing a long variant of the hibernation-promoting factor (SaHPF) that we solved using cryo-electron microscopy. Our reconstructions reveal that the N-terminal domain (NTD) of SaHPF binds to the 30S subunit as observed for shorter variants of HPF in other species. The C-terminal domain (CTD) of SaHPF protrudes out of each ribosome in order to mediate dimerization. Using NMR, we characterized the interactions at the CTD-dimer interface. Secondary interactions are provided by helix 26 of the 16S ribosomal RNA. We also show that ribosomes in the 100S particle adopt both rotated and unrotated conformations. Overall, our work illustrates a specific mode of ribosome dimerization by long HPF, a finding that may help improve the selectivity of antimicrobials.

Effects of functional feed additives based on the fungus Fusarium.S and organic acids were studied. The research studied corporal parameters, the safety, growth and development of young turkeys and pigs. It was found that the Asido Bio-TCIT feed additive improves the physiological state of piglets and turkey poults, reduces feed conversion, increases live weight and profitability of meat production.

It was found that, in accordance with the selected analysis criteria, in the studied animal population in 17.05 % of cows, FPR corresponded to the optimal values, and in 82.95 % it deviated to the lower side and amounted to 1.10 or less. FPR tended to decrease as the milk productivity of animals increased, and increased as soon as the milk productivity of animals began to decrease in the dynamics of milk days. In the group of animals with FPR 1.10 or less, the content of BHBA in milk significantly (by 80.0 %, p <0.01) exceeded the content of BHBA in animals with normal FPR val-ues. In cows with a normal FPR value, the level of acetone in milk was higher than the threshold by 28.57 %, while in animals with low FPR values, the established significant excess was 141.43 % (p <0.05). With the deviation of the FPR downward, an average negative reliable relationship of this indicator with the level of acetone was revealed (r = -0.572, p <0.01). Between the content of BHBA and acetone, an average positive significant relationship was established with FPR less than 1.10 and with FPR from 1.11-1.50, and in the first case, the relationship is stronger.