Dang C V, Niwano M, Ryu J, Taylor B L
J Bacteriol. 1986 Apr;166(1):275-80. doi: 10.1128/jb.166.1.275-280.1986.
Mutants of Escherichia coli and Salmonella typhimurium that were deficient in protein methylesterase activity encoded by cheB had an inverted response to oxygen; they were repelled by concentrations of oxygen that attract wild-type bacteria. Normal responses to oxygen and phosphotransferase substrates were observed in mutants that were deficient in protein methyltransferase (CheR) and the methyl-accepting transducing proteins (Tsr, Tar, Trg). However, the methylation-independent response to oxygen was modified by the loss of esterase activity. The inversion was apparently effected by the amidated Tsr protein present in cheB tsr+ mutants because aerotaxis was normal in cheB tsr strains. Chemotaxis to phosphotransferase sugars was normal in cheB mutants provided the extreme clockwise bias of the flagellar motors was modified to increase the probability of counterclockwise rotation.
缺乏由cheB编码的蛋白质甲酯酶活性的大肠杆菌和鼠伤寒沙门氏菌突变体对氧气有反向反应；它们会被吸引野生型细菌的氧气浓度所排斥。在缺乏蛋白质甲基转移酶（CheR）和甲基接受转导蛋白（Tsr、Tar、Trg）的突变体中观察到对氧气和磷酸转移酶底物的正常反应。然而，酯酶活性的丧失改变了对氧气的非甲基化反应。这种反向显然是由cheB tsr+突变体中存在的酰胺化Tsr蛋白引起的，因为在cheB tsr菌株中趋氧性是正常的。只要鞭毛马达的极端顺时针偏向被改变以增加逆时针旋转的概率，cheB突变体对磷酸转移酶糖的趋化性就是正常的。
