PMID:374403

Citation	Munch-Petersen, A, Mygind, B, Nicolaisen, A and Pihl, NJ (1979) Nucleoside transport in cells and membrane vesicles from Escherichia coli K12.J. Biol. Chem. 254:3730-7
Abstract	Osmotic shock treatment of cells of Escherichia coli K12 caused a reduction in the transport of nucleosides into the cells. The strains used carried mutations in the nucleoside catabolizing enzymes. This indicated that the decrease in transport capacity was not due to loss of these enzymes during the shock treatment. Membrane vesicles, prepared from the same strains, showed a limited transport of cytidine, deoxycytidine, and uridine. Transport of purine nucleosides and of thymidine was very low in vesicles lacking the appropriate nucleoside phosphorylases and no significant stimulation was observed if the nucleoside phosphorylases were present in the membrane vesicles. These results all indicate that components outside the cytoplasmic membrane are important for nucleoside transport. Selection for resistance to fluorodeoxycytidine yielded mutants which were unable to transport any nucleoside, even when the nucleoside phosphorylases were present in high amounts. This finding is consistent with a requirement for a specific transport process prior to the initial enzymatic attack on the incoming nucleoside.
Links	PubMed
Keywords	Biological Transport; Biological Transport, Active; Cell Membrane; Deoxyribonucleosides; Escherichia coli; Genotype; Kinetics; Ribonucleotides; Species Specificity; Uridine
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Phenotype of	Taxon Information	Genotype Information (if known)	Condition Information	OMP ID	OMP Term Name	ECO ID	ECO Term Name	Notes	Status
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: S0 1145 NCBI Taxon ID: 83333	Genotype of Reference Strain: nupC Genotype of Experimental Strain : nupC	Reference Condition:					Resistant to Fluorodeoxyuridine. The genotype not described
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: S0 1131 NCBI Taxon ID: 83333	Genotype of Reference Strain: nupG Genotype of Experimental Strain : nupG	Reference Condition:					Resistance to Fluorodeoxyuridine. Genotype not described
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: S0 1130 NCBI Taxon ID: 83333	Genotype of Reference Strain: nupC nupG Genotype of Experimental Strain : nupC nupG -	Reference Condition:	0000276	increased resistance to antimicrobial compound			Sensitivity to showdomycin, figure 5
a single strain under different conditions	Taxon: Escherichia coli Strain: K-12 Substrain: S0 1131 NCBI Taxon ID: 83333	Genotype of Reference Strain: nupG nupC Genotype of Experimental Strain : nupG nupC -	Reference Condition:	0000276	increased resistance to antimicrobial compound			Resistant to showdomycin, figure 5
a mutation or genetic difference within a strain	Taxon: Escherichia coli Strain: K-12 Substrain: S0 861 NCBI Taxon ID: 83333	Genotype of Reference Strain: nupG Genotype of Experimental Strain : nupG	Reference Condition:					Resistance to 5-fluoro 2'deoxycytidine, figure 2A
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