Localization of polyamine enhancement of protein synthesis to subcellular components of Escherichia coli and Pseudomonas sp. strain Kim.
At 5 mM Mg2+, spermidine stimulation of polyphenylalanine synthesis by cell-free extracts of Escherichia coli was found to be about 30 times greater than that by extracts of Pseudomonas sp. strain Kim, a unique organism which lacks detectable levels of spermidine. By means of reconstitution experiments, the target of spermidine stimulation was localized to the protein fraction of the highspeed supernatant component (S-100) of E. coli and was absent from, or deficient in, the S-100 fraction of Pseudomonas sp. strain Kim. The spermidine stimulation did not appear to be due to the presence in the E. coli S-100 fraction of ribosomal protein S1, elongation factors, or E. coli aminoacyl-tRNA synthetases. The failure to observe spermidine stimulation by the Pseudomonas sp. strain Kim S-100 fraction was also not due to a spermidine-enhanced polyuridylic acid degradation. The synthesis of polyphenylalanine by Pseudomonas sp. strain Kim extracts was stimulated by putrescine and by S-(+)-2-hydroxyputrescine to a greater degree than was synthesis by E. coli extracts. The enhancement by putrescine and by S-(+)-2-hydroxyputrescine with Pseudomonas sp. strain Kim extracts was found to be due to effects on its ribosomes.
D001426:Bacterial Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism* / Q000648:ultrastructure; D010452:Peptide Biosynthesis; D010455:Peptides; D011073:Polyamines / Q000494:pharmacology*; D011549:Pseudomonas / Q000378:metabolism*; D011700:Putrescine / Q000031:analogs & derivatives / Q000494:pharmacology; D012270:Ribosomes / Q000187:drug effects; D013095:Spermidine / Q000494:pharmacology; D013347:Subcellular Fractions / Q000032:analysis
D001426:Bacterial Proteins; D010455:Peptides; D011073:Polyamines; C012001:polyphenylalanine; C002952:2-hydroxyputrescine; D013095:Spermidine; D011700:Putrescine