Department of Biochemistry and Molecular Biology, Biomedicine Institute University of Barcelona (IBUB), Faculty of Pharmacy, University of Barcelona, Av. Diagonal 643, Barcelona 08028, Spain.
Can J Microbiol. 2009 Nov;55(11):1319-22. doi: 10.1139/w09-090.
The yiaK-S operon is required for aerobic growth on L-ascorbate in several Enterobacteriaceae. Here we present evidence that the yiaX2 gene belonging to the yiaK-S operon of Klebsiella pneumoniae 13882, which encodes a protein similar to the putative transporters classified as the major facilitator superfamily, is involved in the uptake of L-ascorbate. Concentration kinetic analysis yielded an apparent K(m) of YiaX2 for L-ascorbate of 161.38 +/-8.28 micromol x L(-1) and a Vmax of 3.81 +/- 0.60 nmol x mg(-1) x min(-1). This carrier uses the energy from electrochemical gradients, since it was inhibited by carbonyl cyanide m-chlorophenylhydrazone, a hydrophobic proton conductor that dissipates proton motive force.
yiaK-S 操纵子是几种肠杆菌科细菌需氧生长 L-抗坏血酸所必需的。在这里，我们提供的证据表明，yiaX2 基因属于肺炎克雷伯氏菌 13882 的 yiaK-S 操纵子，编码一种与假定转运蛋白相似的蛋白质，被分类为主要易化因子超家族，参与 L-抗坏血酸的摄取。浓度动力学分析得出 YiaX2 对 L-抗坏血酸的表观 K(m)为 161.38 +/-8.28 micromol x L(-1)，Vmax 为 3.81 +/- 0.60 nmol x mg(-1) x min(-1)。这种载体利用电化学梯度的能量，因为它被羰基氰化物 m-氯苯腙抑制，后者是一种疏质子导体，会耗散质子动力势。
