Ferguson Gail P, Datta Anup, Baumgartner John, Roop R Martin, Carlson Russ W, Walker Graham C
Biology Department, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
Proc Natl Acad Sci U S A. 2004 Apr 6;101(14):5012-7. doi: 10.1073/pnas.0307137101. Epub 2004 Mar 24.
Sinorhizobium meliloti, a legume symbiont, and Brucella abortus, a phylogenetically related mammalian pathogen, both require the bacterial-encoded BacA protein to establish chronic intracellular infections in their respective hosts. We found that the bacterial BacA proteins share sequence similarity with a family of eukaryotic peroxisomal-membrane proteins, including the human adrenoleukodystrophy protein, required for the efficient transport of very-long-chain fatty acids out of the cytoplasm. This insight, along with the increased sensitivity of BacA-deficient mutants to detergents and cell envelope-disrupting agents, led us to discover that BacA affects the very-long-chain fatty acid (27-OHC28:0 and 29-OHC30:0) content of both Sinorhizobium and Brucella lipid A. We discuss models for how BacA function affects the lipid-A fatty-acid content and why this activity could be important for the establishment of chronic intracellular infections.
苜蓿中华根瘤菌是一种豆科共生菌，而流产布鲁氏菌是一种在系统发育上相关的哺乳动物病原体，它们都需要细菌编码的BacA蛋白在各自宿主中建立慢性细胞内感染。我们发现细菌的BacA蛋白与一类真核过氧化物酶体膜蛋白具有序列相似性，包括人类肾上腺脑白质营养不良蛋白，该蛋白是超长链脂肪酸从细胞质中有效转运所必需的。这一发现，以及BacA缺陷型突变体对去污剂和细胞包膜破坏剂的敏感性增加，使我们发现BacA会影响苜蓿中华根瘤菌和布鲁氏菌脂多糖中超长链脂肪酸（27-羟基二十四烷酸和29-羟基三十六烷酸）的含量。我们讨论了BacA功能如何影响脂多糖脂肪酸含量的模型，以及为什么这种活性对建立慢性细胞内感染可能很重要。
