Novel sensory adaptation mechanism in bacterial chemotaxis to oxygen and phosphotransferase substrates.
Novel sensory adaptation mechanism in bacterial chemotaxis to oxygen and phosphotransferase substrates.
复制标题
细菌对氧和磷酸转移酶底物趋化的新感觉适应机制。
DOI：
10.1073/pnas.79.1.11
复制
发表时间：
1982
影响因子：
11.1
通讯作者：
B. L. Taylor
中科院分区：
文献类型：
--
作者：
M. Niwano;B. L. Taylor
甲基化在细菌对许多引诱剂的化学感受性反应中的参与已经通过几个实验室的研究清楚地确立。已经假设鼠伤寒沙门氏菌和大肠杆菌对所有引诱剂的适应涉及跨膜甲基接受趋化性蛋白的甲基化。该反应中的甲基供体是S-腺苷-L-甲硫氨酸，蛋白质甲基转移酶是cheR基因的产物。相反，发现对氧和磷酸转移酶底物的适应不依赖于该甲基化系统。在大肠coli AW 660（tsr tar trg），其缺乏已知的甲基接受趋化性蛋白，趋化性对于氧和对于磷酸转移酶系统的底物如D-甘露糖、D-葡萄糖和N-乙酰基-D-葡糖胺是正常的。当S-腺苷-L-甲硫氨酸通过甲硫氨酸饥饿或通过加入1-氨基环戊烷-1-羧酸而耗尽时，野生型E. coli和革兰氏阳性菌S.鼠伤寒。然而，对氧和磷酸转移酶底物的适应不依赖于S-腺苷-L-甲硫氨酸和cheR产物。这些结果表明，细菌的感觉适应存在甲基化非依赖性和甲基化依赖性机制。
The involvement of methylation in the chemosensory response of bacteria to many attractants has been clearly established by studies in several laboratories. It has been assumed that adaptation of Salmonella typhimurium and Escherichia coli to all attractants involves methylation of a transmembrane methyl-accepting chemotaxis protein. The methyl donor in this reaction is S-adenosyl-L-methionine, and the protein methyltransferase is the product of the cheR gene. In contrast, adaptation to oxygen and phosphotransferase substrates were found to be independent of this methylation system. In E. coli AW660 (tsr tar trg), which lacks the known methyl-accepting chemotaxis proteins, chemotaxis was normal to oxygen and to substrates of the phosphotransferase system such as D-mannose, D-glucose, and N-acetyl-D-glucosamine. When S-adenosyl-L-methionine was depleted by methionine starvation or by addition of 1-aminocyclopentane-1-carboxylic acid, methylation-dependent adaptation to serine, aspartate, and ribose was defective in wild-type E. coli and S. typhimurium. However, adaptation to oxygen and phosphotransferase substrates was independent of S-adenosyl-L-methionine and the cheR product. These results suggest that there are methylation-independent and methylation-dependent mechanisms for sensory adaptation in bacteria.