Maghnouj A, de Sousa Cabral T F, Stalon V, Vander Wauven C
Laboratoire de Microbiologie de l'Université Libre de Bruxelles, B-1070 Brussels, Belgium.
J Bacteriol. 1998 Dec;180(24):6468-75. doi: 10.1128/JB.180.24.6468-6475.1998.
The arginine deiminase pathway enables Bacillus licheniformis to grow anaerobically on arginine. Both the presence of arginine and anaerobiosis are needed to trigger induction of the pathway. In this study we have cloned and sequenced the arc genes encoding the pathway. They appear clustered in an operon-like structure in the order arcA (arginine deiminase), arcB (ornithine carbamoyltransferase), arcD (putative arginine-ornithine antiporter), arcC (carbamate kinase). It was found that B. licheniformis has an arginine repressor, ArgR, homologous to the B. subtilis arginine repressor AhrC. Mutants affected in argR were isolated. These mutants have lost both repression by arginine of the anabolic ornithine carbamoyltransferase and induction of the arginine deiminase pathway. Electrophoretic band shift experiments and DNase I footprinting revealed that in the presence of arginine, ArgR binds to a site upstream from the arc promoter. The binding site is centered 108 nucleotides upstream from the transcription start point and contains a single Arg box.
精氨酸脱亚氨酶途径使地衣芽孢杆菌能够在精氨酸上进行厌氧生长。精氨酸的存在和厌氧环境都是触发该途径诱导所必需的。在本研究中，我们克隆并测序了编码该途径的arc基因。它们似乎以操纵子样结构成簇排列，顺序为arcA（精氨酸脱亚氨酶）、arcB（鸟氨酸氨甲酰基转移酶）、arcD（假定的精氨酸-鸟氨酸反向转运蛋白）、arcC（氨基甲酸激酶）。发现地衣芽孢杆菌有一种精氨酸阻遏蛋白ArgR，与枯草芽孢杆菌的精氨酸阻遏蛋白AhrC同源。分离出了在argR中受影响的突变体。这些突变体既失去了精氨酸对合成代谢鸟氨酸氨甲酰基转移酶的阻遏作用，也失去了精氨酸脱亚氨酶途径的诱导作用。电泳带迁移实验和DNase I足迹实验表明，在精氨酸存在的情况下，ArgR与arc启动子上游的一个位点结合。结合位点位于转录起始点上游108个核苷酸处的中心位置，并且包含一个单一的Arg框。
