68 research outputs found
Pseudouridine at position 55 in tRNA controls the contents of other modified nucleotides for low-temperature adaptation in the extreme-thermophilic eubacterium Thermus thermophilus
Pseudouridine at position 55 (ĪØ55) in eubacterial tRNA is produced by TruB. To clarify the role of the ĪØ55 modification, we constructed a truB gene disruptant (ĪtruB) strain of Thermus thermophilus which is an extreme-thermophilic eubacterium. Unexpectedly, the ĪtruB strain exhibited severe growth retardation at 50Ā°C. We assumed that these phenomena might be caused by lack of RNA chaperone activity of TruB, which was previously hypothetically proposed by others. To confirm this idea, we replaced the truB gene in the genome with mutant genes, which express TruB proteins with very weak or no enzymatic activity. However the growth retardation at 50Ā°C was not rescued by these mutant proteins. Nucleoside analysis revealed that Gm18, m5s2U54 and m1A58 in tRNA from the ĪtruB strain were abnormally increased. An in vitro assay using purified tRNA modification enzymes demonstrated that the ĪØ55 modification has a negative effect on Gm18 formation by TrmH. These experimental results show that the ĪØ55 modification is required for low-temperature adaptation to control other modified. 35S-Met incorporation analysis showed that the protein synthesis activity of the ĪtruB strain was inferior to that of the wild-type strain and that the cold-shock proteins were absence in the ĪtruB cells at 50Ā°C
Biperiodic L-Support Disk and Washer Structure (NUCLEAR SCIENCE RESEARCH FACILITY-Beams and Fundamental Reaction)
A high power model of the biperiodic L-support Disk and Washer structure for electron acceleration is fabricated and under test. Two 1.2m long accelerating tubes are coupled by a bridge coupler, which has an RF coupler, a vacuum port, and three frequency tuners. Each end of the bridge-coupled tube set is terminated by a full-cell endplate for the accelerating mode
Effect of Film Crystallinity on Environmental Stress Cracking in Polyester Film Laminated on Steel Sheets for Interior Building Materials
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Effect of Contact Cooling Length after the Laminating Rolls on Formation of Amorphous Layer of Biaxially Oriented Polyester Film in the Laminating Process
Biperiodic L-Support Disk and Washer Structure (NUCLEAR SCIENCE RESEARCH FACILITY-Beams and Fundamental Reaction)
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