Protein synthesis by the psychrophiles Bacillus psychrophilus and Bacillus insolitus

Abstract

Protein synthesis by whole cells of two psychrophilic bacteria, Bacillus psychrophilus and Bacillus insolitus, directly corresponded to the growth of these organisms at 5, 20 and 30C, with a smaller total amount of growth and protein synthesis occurring at 30C than at 20C. When the effect of temperature on protein synthesis was examined using extracts, the capability to carry out poly U directed incorporation of 14C-L-phenylalanine into protein was inhibited by 30C as compared to 5C. The temperature sensitivity of the cell-free protein synthesizing systems was not due to the presence of heat-sensitive aminoacyl-tRNA synthetases. Investigation of the effect of separately heating at 30C washed ribosome (W-RIB) and supernatant (IS-100) fractions prepared from these microorganisms, followed by recombination and reaction at 15C, showed that the temperature sensitivity of the protein synthesis resided in the ribosomal fraction of the cells

Effects of Ribosomes and Intracellular Solutes on Activities and Stabilities of Elongation Factor 2 Proteins from Psychrotolerant and Thermophilic Methanogens

“…The translation system is essential to cell growth and has been shown to be a critical target in the cold shock response and for adapting to growth at low temperatures (4,5,16,40,41). In the absence of other adaptive mechanisms that may increase the activity of EF-2, maintaining EF-2 levels steady at low temperatures may ensure that ribosome translocation remains adequate.…”

Effect of Proline and K+on the Stimulation of Cellular Activities inEscherichia coliK-12 under High Salinity

“…The radioactivity remaining on the filters was determined with a liquid scintillation spectrometer (Tri-Carb 2001TR, Perkin Elmer, Wellesley, MA, U.S.A.). To determine the incorporation of L-[ 3 H]proline by intact cells, the method of Bobier et al 16) was used with minor modifications. At designated time intervals, 0.5 ml of the reaction medium was injected into 0.5 ml of 10% trichloroacetic acid (TCA).…”

Responses of Microorganisms to Temperature

“…Nevertheless, protein synthesis ceases at temperatures much closer to the maximum growth temperature. In vitro protein synthesis experiments with ribosomes and supernatant fractions from psychrophilic Bacilli (B. insolitus and B. psychrophilus) showed inactivation of ribosomes by a treatment of 10 min at 30°C, whereas in the same conditions the supernatant remained active (BOBIER et al 1972). …”