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Nucleoside transport systems in Escherichia coli K12: Specificty and regulation
Author(s) -
MunchPetersen Agnete,
Mygind Benete
Publication year - 1976
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.1040890410
Subject(s) - nucleoside , escherichia coli , pyrimidine , biochemistry , mutant , enzyme , chemistry , guanine , gene , transport system , biology , nucleotide , transport engineering , engineering
Two nucleoside transport systems have been verified and separated by mating and recombination experiments. The recipient strain was a mutant which is negative for transport of all nucleosides. The two systems differ in specificity and in regulation. One system transports pyrimidine and adenine in specificity and in regulation. One system transports pyrimidine and adenine nucleosides, but not guanine nucleosides. It is regulated by the cyt R gene. The other system transports all nucleosides and is regulated by the cyt R as well as by the deo R genes. Enzyme assays performed on whole cells of strains, able or unable to transport nucleosides, indicate that the nucleoside catabolizing enzymes are located inside the permeability barrier of the cell.