The N4-hydroxycytidine reduction system in toluenized cells of Salmonella typhimurium.
1. Enzymatic reduction of N4-hydroxycytidine to cytidine in Salmonella typhimurium is highly specific. The reaction occurs only at the nucleoside level. Free base or its 1-methyl analogue is not reduced. 2. The pH optimum shows a broad plateau with a maximum at pH 7.0. The apparent Km value, estimated in the toluene-treated cells, is 4.8 mM and Vmax 1.4 nmoles/min/mg of wet bacterial weight. The reaction is NADH-dependent, although in toluenized bacterial cells it can occure without addition of any exogenous factor.
D003562:Cytidine / Q000031:analogs & derivatives* / Q000378:metabolism; D005182:Flavin-Adenine Dinucleotide / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009243:NAD / Q000378:metabolism; D010088:Oxidoreductases / Q000032:analysis; D012486:Salmonella typhimurium / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature; D014529:Uridine / Q000378:metabolism
D009243:NAD; D005182:Flavin-Adenine Dinucleotide; D003562:Cytidine; D010088:Oxidoreductases; D014529:Uridine