de Crécy-Lagard V, Bouvet O M, Lejeune P, Danchin A
Unité de Régulation de l'Expression Génétique, Institut National de la Santé et de la Recherche Médicale Unité 199, Institut Pasteur, Paris, France.
J Biol Chem. 1991 Sep 25;266(27):18154-61.
In Xanthomonas campestris pv. campestris, fructose is transported and phosphorylated into fructose 1-phosphate through a phosphoenolpyruvate-dependent phosphotransferase system. The nucleotide sequence of the fruA gene encoding the phosphotransferase system permease specific of fructose (EIIFru) was determined. The fructose 1-phosphate produced by the phosphotransferase system is phosphorylated into fructose 1,6-bisphosphate by a 1-phosphofructokinase. This enzyme was characterized and the corresponding gene (fruK) was sequenced. Sequence comparisons revealed that FruK is a member of a new family of ATP-binding proteins composed of sugar (or sugar-phosphate) kinases. In phosphotransferase system-deficient strains, fructose can still be transported by an unidentified permease. The intracellular fructose is then phosphorylated by a multimeric fructokinase of 135 kDa specific for fructose and inhibited by fructose, fructose 1,6-bisphosphate, and mannose. Several other enzymes of fructose metabolism were assayed and a potential pathway for fructose catabolism is presented.
在野油菜黄单胞菌野油菜致病变种中，果糖通过磷酸烯醇式丙酮酸依赖性磷酸转移酶系统被运输并磷酸化为1-磷酸果糖。测定了编码果糖特异性磷酸转移酶系统通透酶（EIIFru）的fruA基因的核苷酸序列。磷酸转移酶系统产生的1-磷酸果糖被1-磷酸果糖激酶磷酸化为1,6-二磷酸果糖。对该酶进行了特性鉴定，并对相应基因（fruK）进行了测序。序列比较表明，FruK是由糖（或糖磷酸）激酶组成的ATP结合蛋白新家族的成员。在磷酸转移酶系统缺陷型菌株中，果糖仍可通过一种未鉴定的通透酶进行运输。然后，细胞内的果糖被一种135 kDa的多聚体果糖激酶磷酸化，该酶对果糖具有特异性，并受果糖、1,6-二磷酸果糖和甘露糖的抑制。对果糖代谢的其他几种酶进行了测定，并提出了果糖分解代谢的潜在途径。
