Lüthi E, Baur H, Gamper M, Brunner F, Villeval D, Mercenier A, Haas D
Mikrobiologisches Institut, Eidgenössische Technische Hochschule, Zürich, Switzerland.
Gene. 1990 Mar 1;87(1):37-43. doi: 10.1016/0378-1119(90)90493-b.
The arginine deiminase (ADI) pathway in Pseudomonas aeruginosa serves to generate ATP. The three enzymes involved, ADI, catabolic ornithine carbamoyltransferase and carbamate kinase, are induced by oxygen limitation and encoded by the contiguous arcABC genes. A 1.5-kb region upstream from arcABC was sequenced and found to contain an open reading frame, arcD, coding for a hydrophobic polypeptide of 52 kDa. The content and distribution of hydrophobic amino acids suggest that the arcD gene product may be a transmembrane protein. When arcD was fused to an Escherichia coli promoter, the ArcD protein was synthesized in E. coli maxicells and detected in the membrane fraction. In sodium dodecyl sulfate-polyacrylamide-gel electrophoresis the ArcD protein migrated like a 32-kDa protein; such anomalous electrophoretic mobility is known for other highly hydrophobic proteins. Mutations in arcD rendered the cells unable to utilize extracellular arginine as an energy source. Since anaerobic arginine consumption and ornithine release are coupled in P. aeruginosa, it is proposed that arcD specifies an arginine: ornithine antiporter or a part thereof. Insertions of IS21 or Tn1725 in arcD had a strong polar effect on the expression of the arcAB enzymes, indicating that the arc genes are organized as an arcDABC operon.
铜绿假单胞菌中的精氨酸脱亚胺酶（ADI）途径用于产生ATP。所涉及的三种酶，即ADI、分解代谢鸟氨酸氨甲酰基转移酶和氨基甲酸激酶，受氧限制诱导，并由相邻的arcABC基因编码。对arcABC上游1.5 kb的区域进行了测序，发现其中包含一个开放阅读框arcD，其编码一个52 kDa的疏水多肽。疏水氨基酸的含量和分布表明，arcD基因产物可能是一种跨膜蛋白。当arcD与大肠杆菌启动子融合时，ArcD蛋白在大肠杆菌的最大细胞中合成，并在膜组分中检测到。在十二烷基硫酸钠-聚丙烯酰胺凝胶电泳中，ArcD蛋白的迁移情况类似于一个32 kDa的蛋白；其他高度疏水的蛋白也有这种异常的电泳迁移率。arcD中的突变使细胞无法利用细胞外精氨酸作为能量来源。由于在铜绿假单胞菌中厌氧精氨酸消耗和鸟氨酸释放是偶联的，因此推测arcD指定了一种精氨酸：鸟氨酸反向转运蛋白或其一部分。IS21或Tn1725插入arcD对arcAB酶的表达有很强的极性效应，表明arc基因被组织成一个arcDABC操纵子。
