Transport of nicotinamide adenine dinucleotide in an unc mutant of Escherichia coli.
The presence and some properties of an NAD+ transport system were examined in PA5, a Mg, Ca-ATPase [EC 3.6.1.3]-defective mutant strain of Escherichia coli W2252. NAD+ uptake was stimulated by exogenous energy sources and dependent on external substrate concentrations with an apparent Km of about 25 micrometer. Most of the radioactivity from [14C]-NAD+ accumulated in the cells was identified as NAD+. [14C]NAD+ uptake was competively inhibited by unlabeled NAD+, NADP+, NMN+ or nicotinamide. Similar uptake activity was also observed in W2252.
D001692:Biological Transport; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D008274:Magnesium; D009154:Mutation; D009243:NAD / Q000378:metabolism*; D009249:NADP / Q000378:metabolism
D009243:NAD; D009249:NADP; D000252:Calcium-Transporting ATPases; D008274:Magnesium