Mutations in the chemotactic response regulator, CheY, that confer resistance to the phosphatase activity of CheZ.
Mutations in the chemotactic response regulator, CheY, that confer resistance to the phosphatase activity of CheZ.
复制标题
趋化反应调节剂 CheY 发生突变，导致对 CheZ 磷酸酶活性产生抗性。
DOI：
10.1111/j.1365-2958.1995.tb02282.x
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发表时间：
1995
影响因子：
3.6
通讯作者：
Simon,MI
中科院分区：
文献类型：
--
作者：
Sanna,MG;Swanson,RV;Bourret,RB;Simon,MI
CheY, a small cytoplasmic response regulator, plays an essential role in the chemotaxis pathway. The concentration of phospho‐CheY is thought to determine the swimming behaviour of the cell: high levels of phospho‐CheY cause bacteria to rotate their flagella clockwise and tumble, whereas low levels of the phos‐phorylated form of the protein allow counter‐ciockwise rotation of the flagella and smooth swimming. The phosphorylation state of CheYin vivois determined by the activity of the phosphoryl donor CheA, and by the antagonistic effect of dephosphorylation of phospho‐CheY. The dephosphorylation rate is controlled by the intrinsic autohydrolytic activity of phospho‐CheY and by the CheZ protein, which accelerates dephosphorylation. We have analysed the effect of CheZ on the dephosphorylation rates of several mutant CheY proteins. Two point mutations were identified which were 50‐fold and 5‐fold less sensitive to the activity of CheZ than was the wild‐type protein. Nonetheless, the phosphorylation and autodephos‐phorylation rates of these mutants, CheY23ND and CheY26KE, were observed to be identical to those of wild‐type CheY in the absence of CheZ. These are the first examples ofCheYmutations that reduce sensitivity to the phosphatase activity of CheZ without being altered in terms of their intrinsic phosphorylation and autodephospborylation rates, interestingly, the residues Asn‐23 and Lys‐26 are located on a face of CheY far from the phosphorylation site (Asp‐57), distinct from the previously described site of inter‐action with the histidine kinase CheA, and partially overlapping with a region implicated in interaction with the flagellar switch.
