title: The nature of the uptake systems for nucleic acid bases in Escherichia coli.
mesh_terms: D001692:Biological Transport; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D011687:Purines / Q000378:metabolism*; D014498:Uracil / Q000378:metabolism*
chemical_list: D011687:Purines; D014498:Uracil