A chemotactic signaling surface on CheY defined by suppressors of flagellar switch mutations.
A chemotactic signaling surface on CheY defined by suppressors of flagellar switch mutations.
复制标题
CheY 上的趋化信号表面由鞭毛开关突变的抑制因子定义。
DOI：
10.1128/jb.174.19.6247-6255.1992
复制
发表时间：
1992
影响因子：
3.2
通讯作者：
Matsumura,P
中科院分区：
文献类型：
--
作者：
Roman,SJ;Meyers,M;Volz,K;Matsumura,P
CheY 是一种反应调节蛋白，它与鞭毛开关装置相互作用，在趋化信号传导过程中调节鞭毛旋转。 CheY 可在体外被磷酸化和去磷酸化，有证据表明 CheY-P 是诱导鞭毛顺时针旋转的激活形式，导致细胞游泳模式的翻滚。鞭毛开关装置是一种复杂的大分子结构，由至少三种基因产物FliG、FliM和FliN组成。对大肠杆菌的遗传分析已确定 fliG 和 fliM 是发生突变的基因，等位基因特异性抑制 cheY 突变，表明这些基因产物之间存在相互作用。我们已经生成了一类 cheY 突变，选择用于显性抑制 fliG 突变。有趣的是，这些 cheY 突变显着抑制了 fliG 和 fliM 突变；这与 CheY 蛋白在信号传导过程中与两个开关基因产物相互作用的想法是一致的。野生型和抑制型 CheY 蛋白的生化特征并未揭示磷酸化特性的改变或磷酸化依赖性 CheY 多聚化的证据。这些数据表明，抑制性 CheY 蛋白在磷酸化后的某个点将趋化信号转导至开关的能力发生了特异性改变。 CheY 晶体结构上抑制氨基酸取代的物理图谱揭示了高度的空间聚类，表明 CheY 的该区域是将趋化信号转导至开关的信号表面。
CheY is the response regulator protein that interacts with the flagellar switch apparatus to modulate flagellar rotation during chemotactic signaling. CheY can be phosphorylated and dephosphorylated in vitro, and evidence indicates that CheY-P is the activated form that induces clockwise flagellar rotation, resulting in a tumble in the cell's swimming pattern. The flagellar switch apparatus is a complex macromolecular structure composed of at least three gene products, FliG, FliM, and FliN. Genetic analysis of Escherichia coli has identified fliG and fliM as genes in which mutations occur that allele specifically suppress cheY mutations, indicating interactions among these gene products. We have generated a class of cheY mutations selected for dominant suppression of fliG mutations. Interestingly, these cheY mutations dominantly suppressed both fliG and fliM mutations; this is consistent with the idea that the CheY protein interacts with both switch gene products during signaling. Biochemical characterization of wild-type and suppressor CheY proteins did not reveal altered phosphorylation properties or evidence for phosphorylation-dependent CheY multimerization. These data indicate that suppressor CheY proteins are specifically altered in the ability to transduce chemotactic signals to the switch at some point subsequent to phosphorylation. Physical mapping of suppressor amino acid substitutions on the crystal structure of CheY revealed a high degree of spatial clustering, suggesting that this region of CheY is a signaling surface that transduces chemotactic signals to the switch.