PnuC and the utilization of the nicotinamide riboside analog 3-aminopyridine in Haemophilus influenzae
PnuC and the utilization of the nicotinamide riboside analog 3-aminopyridine in Haemophilus influenzae
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DOI：
10.1128/aac.48.12.4532-4541.2004
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发表时间：
2004-12-01
影响因子：
4.9
通讯作者：
Reidl, J
中科院分区：
文献类型：
--
作者：
Sauer, E;Merdanovic, M;Reidl, J
先前已对流感嗜血杆菌摄取 NAD 和烟酰胺核苷的利用途径进行了表征。我们现在报告 PnuC 的细胞位置、拓扑结构和底物特异性。流感嗜血杆菌的pnuC仅与大肠杆菌和鼠伤寒沙门氏菌的pnuC有远缘关系。当大肠杆菌 PnuC 在流感嗜血杆菌 pnuC 突变体中表达时，它只能吸收烟酰胺核苷，而不能吸收烟酰胺单核苷酸。因此，我们假设 PnuC 转运蛋白总体上对烟酰胺核苷具有特异性。早期研究表明，3-氨基吡啶衍生物（例如 3-氨基吡啶腺嘌呤二核苷酸）可抑制流感嗜血杆菌的生长。通过测试 NAD 利用途径中具有突变的特征菌株，我们发现 3-氨基吡啶核苷对流感嗜血杆菌有抑制作用，并被 NAD 加工和烟酰胺核苷途径吸收。 3-氨基吡啶核苷在 pnuC(+) 背景下得到有效利用。此外，我们证明了 3-氨基吡啶腺嘌呤二核苷酸的再合成是由 NadR 产生的。对 3-氨基吡啶核苷耐药的流感嗜血杆菌分离株进行了表征，并且可以检测到 nadR 的突变。我们还测试了巴氏杆菌科的其他物种、多杀性巴氏杆菌和伴放线放线杆菌，发现3-氨基吡啶核苷不充当生长抑制剂；因此，3-氨基吡啶核苷是一种宿主范围非常窄的抗感染剂。
The utilization pathway for the uptake of NAD and nicotinamide riboside was previously characterized for Haemophilus influenzae. We now report on the cellular location, topology, and substrate specificity of PnuC. pnuC of H. influenzae is only distantly related to pnuC of Escherichia coli and Salmonella enterica serovar Typhimurium. When E. coli PnuC was expressed in an H. influenzae pnuC mutant, it was able to take up only nicotinamide riboside and not nicotinamide mononucleotide. Therefore, we postulated that PnuC transporters in general possess specificity for nicotinamide riboside. Earlier studies showed that 3-aminopyridine derivatives (e.g., 3-aminopyridine adenine dinucleotide) are inhibitory for H. influenzae growth. By testing characterized strains with mutations in the NAD utilization pathway, we show that 3-aminopyridine riboside is inhibitory to H. influenzae and is taken up by the NAD-processing and nicotinamide riboside route. 3-Aminopyridine riboside is utilized effectively in a pnuC(+) background. In addition, we demonstrate that 3-aminopyridine adenine dinucleotide resynthesis is produced by NadR. 3-Aminopyridine riboside-resistant H. influenzae isolates were characterized, and mutations in nadR could be detected. We also tested other species of the family Pasteurellaceae, Pasteurella multocida and Actinobacillus actinomycetemcomitans, and found that 3-aminopyridine riboside does not act as a growth inhibitor; hence, 3-aminopyridine riboside represents an anti-infective agent with a very narrow host range.