Kondoh H
J Bacteriol. 1980 May;142(2):527-34. doi: 10.1128/jb.142.2.527-534.1980.
Some mutants defective in chemotaxis show incessant tumbling behavior and are called tumbling mutants. Previously described tumbling mutations lie in two genes, cheB and cheZ (41.5 min on Escherichia coli map). Genetic analysis of various tumbling mutants, however, revealed that two more genetic loci, cheC (43 min) and cheE (99.2 min), could also mutate to produce tumbling mutants. The genetic map around cheC was revised: his flaP flaQ flaR flbD flaA (= cheC) flaE. flbD is a new gene. When cells were starved for methionine, the tumbling mutants changed their swimming behavior depending on the che gene mutated. cheZ mutants, like wild-type bacteria, ceased tumbling shortly after removal of methionine. The tumbling of cheB or cheE mutants was depressed after prolonged methionine starvation in the presence of a constant level of an attractant. cheC tumbling mutants appeared unique in that they did not cease tumbling even when cells were deprived of methionine. By contrast, arsenate treatment of the tumbling mutants resulted in smooth swimming of the cells in every case. These results suggest that two different processes are involved in regulation of tumbling; one requiring methionine and the other requiring some phosphorylated compound.
一些在趋化性方面存在缺陷的突变体表现出持续翻滚行为，被称为翻滚突变体。先前描述的翻滚突变位于两个基因cheB和cheZ中（在大肠杆菌基因图谱上位于41.5分钟处）。然而，对各种翻滚突变体的遗传分析表明，另外两个基因位点cheC（43分钟）和cheE（99.2分钟）也可能发生突变产生翻滚突变体。对cheC周围的遗传图谱进行了修订：his flaP flaQ flaR flbD flaA（= cheC）flaE。flbD是一个新基因。当细胞缺乏甲硫氨酸时，翻滚突变体根据发生突变的che基因改变其游动行为。与野生型细菌一样，cheZ突变体在去除甲硫氨酸后不久就停止了翻滚。在存在恒定水平引诱剂的情况下，经过长时间甲硫氨酸饥饿后，cheB或cheE突变体的翻滚受到抑制。cheC翻滚突变体显得独特，因为即使细胞被剥夺甲硫氨酸，它们也不会停止翻滚。相比之下，用砷酸盐处理翻滚突变体在每种情况下都会使细胞平稳游动。这些结果表明，翻滚调节涉及两个不同的过程；一个需要甲硫氨酸，另一个需要一些磷酸化化合物。
