Koiwai O, Minoshima S, Hayashi H
J Biochem. 1980 May;87(5):1365-70. doi: 10.1093/oxfordjournals.jbchem.a132876.
Chemotactic Escherichia coli contains five major methyl-accepting proteins. Three of them were identified as the product of tsr gene, tar gene and peptide elongation factor Tu. Electrophoretic analysis of sulfur-labeled proteins and methyl-labeled proteins from trg mutants, which lost the ability of chemotaxis only towards ribose, galactose and their analogs, showed that the product of trg gene was another methyl-accepting protein i.e. a methyl-accepting chemotaxis protein for ribose and galactose (trg-MCP). The last methylatable protein, named as MCP-IV, seems to be involved in chemosensory transduction (accompanying paper). Thus, it is possible that chemosensory transduction in E. coli involves four species of MCP, although no genetic evidence for MCP-IV has yet been found. A hypothesis relating a change in the methylation of MCP with a movement of ions is presented.
趋化性大肠杆菌含有五种主要的甲基接受蛋白。其中三种被鉴定为tsr基因、tar基因和肽延伸因子Tu的产物。对trg突变体（该突变体仅丧失了对核糖、半乳糖及其类似物的趋化能力）的硫标记蛋白和甲基标记蛋白进行电泳分析，结果表明trg基因的产物是另一种甲基接受蛋白，即核糖和半乳糖的甲基接受趋化蛋白（trg-MCP）。最后一种可甲基化的蛋白，命名为MCP-IV，似乎参与化学感受转导（附文）。因此，尽管尚未找到MCP-IV的遗传证据，但大肠杆菌中的化学感受转导可能涉及四种MCP。本文提出了一个关于MCP甲基化变化与离子移动相关的假说。
