Hooper L V, Xu J, Falk P G, Midtvedt T, Gordon J I
Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Proc Natl Acad Sci U S A. 1999 Aug 17;96(17):9833-8. doi: 10.1073/pnas.96.17.9833.
Little is known about how members of the indigenous microflora interact with their mammalian hosts to establish mutually beneficial relationships. We have used a gnotobiotic mouse model to show that Bacteroides thetaiotaomicron, a component of the intestinal microflora of mice and humans, uses a repressor, FucR, as a molecular sensor of L-fucose availability. FucR coordinates expression of an operon encoding enzymes in the L-fucose metabolic pathway with expression of another locus that regulates production of fucosylated glycans in intestinal enterocytes. Genetic and biochemical studies indicate that FucR does this by using fucose as an inducer at one locus and as a corepressor at the other locus. Coordinating this commensal's immediate nutritional requirements with production of a host-derived energy source is consistent with its need to enter and persist within a competitive ecosystem.
关于本土微生物群落成员如何与它们的哺乳动物宿主相互作用以建立互利关系，我们所知甚少。我们利用无菌小鼠模型表明，小鼠和人类肠道微生物群的一个组成部分——多形拟杆菌，将一种阻遏物FucR用作L-岩藻糖可用性的分子传感器。FucR协调L-岩藻糖代谢途径中编码酶的操纵子的表达与另一个调节肠道肠细胞中岩藻糖基化聚糖产生的位点的表达。遗传和生化研究表明，FucR通过在一个位点使用岩藻糖作为诱导剂，在另一个位点使用岩藻糖作为共阻遏物来实现这一点。将这种共生菌的即时营养需求与宿主衍生能量源的产生相协调，与其进入并在竞争激烈的生态系统中持续存在的需求是一致的。
