Specific incorporation of glycine into bacterial lipopolysaccharide. Novel function of specific transfer ribonucleic acids.

It has been found that the bacterial endotoxins (lipopolysaccharides, LPSs) contain some amino acids and glycine is the most abundant amino acid in the polysaccharide core preparations of LPSs of gram-negative bacteria. Until now nothing was known about the mechanism of amino acid incorporation into the lipopolysaccharide core. We found that one out of three glycyl-tRNAs(Gly) from Escherichia coli is the donor of amino acid and is the substrate for a putative aminoacyl-tRNA:LPS transferase. We have isolated, purified this tRNA and determined its nucleotide sequence to be major E.coli tRNA(3Gly). This tRNA(Gly) (anticodon GCC) conserved the tRNA structural features. The assay for determination of the specific incorporation of glycine into the lipopolysaccharide was also invented and described.     

The primary structure of wheat germ tRNAArg--the substrate for arginyl-tRNAArg:protein transferase

Besides its major role in protein synthesis, wheat germ arginyl-tRNAArg can serve as an amino acid donor in an enzymatic reaction to bovine serum albumin catalysed by the enzyme arginyl-tRNAArg: protein transferase. The nucleotide sequence of the tRNAArg involved in this reaction was determined to be: pG-A-C-U-C-C-G-U-m1G-m2G-C-C-C-A-A-D-Gm-G-A-X-A-A-G-G-C-m2(2) G-C-U-G-G-U-Cm-U-I-C-G-m2A-A-A-C-C-A-G-A-G-A-D-U-m5C-U-G-G-G-T-psi -C-G-m1 A-U-C-C-C-C-A-G-C-G-G-A-G-U-C-G-C-C-AOH. We suggest that the decapentanucleotide 5'-G-U-Pu-m2G-C-N-C-A-A-D-Gm-G-A-X-A-3', localized in the D-region, interacts specifically with the protein transferase.     

The nucleotide sequence of ribosomal 5S RNA from Rhizobium meliloti: comparison with 5S rRNA of Agrobacterium

The complete nucleotide sequence of R. meliloti 5S ribosomal RNA has been determined and compared with the already known sequence of A. tumefaciens 5S rRNA (Vandenberghe et al., 1985, Eur. J. Biochem., 149, 537-542) and of other 5S rRNAs from Rodobacteria Alpha-2 (Wolters et al., 1988, Nucleic Acids Res., 16, rl-r70). The differences found at eight positions (23, 73, 83, 72 in helical fragments; 16, 40, 88 in loops; 54 in bulge), which might affect secondary structures of 5S rRNA, are small. Moreover, the sequence analysis specifies both variable and common positions in 5S rRNA secondary structure of Rodobacteria Alpha-2.     

Accumulation of cesium and radiocesium in forest litter in selected regions of poland and its influence on litter-to-mushroom transfer factor

The aim of this work was to check whether the stable cesium content in forest litter affects the value of radiocesium from litter-to-mushroom transfer factorTf or not. Total cesium in litter, measured by AAS, varied from 0.1–2.7 μg/g. These data, combined with earlier results for mushrooms, showed no simple correlation forTf. More complex relationships provided very high correlation coefficients, but their validity needs further investigation.     

Enhancement of symbiotic nitrogen fixation by vitamin-secreting fluorescent Pseudomonas

Fluorescent Pseudomonas sp. strain 267 promotes growth of nodulated clover plants under gnotobiotic conditions. In the growth conditions (60 M FeCl₃), the production of siderophores of the pseudobactin-pyoverdin group was repressed. Plant growth enhancement results from secretion of B vitamins by Pseudomonas sp. strain 267. This was proven by stimulation of clover growth by naturally auxotrophic strains of Rhizobium leguminosarum bv. trifolii and marker strains E. coli thi^- and R. meliloti pan^- in the presence of the supernatant of Pseudomonas sp. strain 267. The addition of vitamins to the plant medium increased symbiotic nitrogen fixation by the clover plants.