MUTANTS IN DISULFIDE BOND FORMATION THAT DISRUPT FLAGELLAR ASSEMBLY IN ESCHERICHIA-COLI
MUTANTS IN DISULFIDE BOND FORMATION THAT DISRUPT FLAGELLAR ASSEMBLY IN ESCHERICHIA-COLI
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DOI：
10.1073/pnas.90.3.1043
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发表时间：
1993-02-01
影响因子：
11.1
通讯作者：
BERG, HC
中科院分区：
文献类型：
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作者：
DAILEY, FE;BERG, HC
我们报告了大肠杆菌突变体(DsbB)的分离和特征，这些突变体在没有胱氨酸存在的情况下无法组装功能鞭毛。从这些突变体获得的鞭毛基体缺失L环和P环。这种组装缺陷似乎是由于不能在P-环蛋白(FlgI)中形成二硫键所致。胱氨酸可抑制dsbB菌株的这一缺陷。我们还发现dsbA菌株[Bardwell，J.C.A.，McGoven，K.&Beckwith，J.(1991)Cell 67,581-589]未能组装P环，显然是由于二硫键形成的类似失败。然而，在dsbA菌株中，胱氨酸并不能完全抑制这一缺陷。因此，FlgI中二硫键的形成是组装所必需的。DsbA可能直接进入那个键，而DsbB的产物(S)在氧化DsbA的过程中起到作用，因此它可以被激活。
We report the isolation and characterization of Escherichia coli mutants (dsbB) that fail to assemble functional flagella unless cystine is present. Flagellar basal bodies obtained from these mutants are missing the L and P rings. This defect in assembly appears to result from an inability to form a disulfide bond in the P-ring protein (FlgI). Cystine suppresses this defect in dsbB strains. We also show that dsbA strains [Bardwell, J. C. A., McGovern, K. & Beckwith, J. (1991) Cell 67, 581-589] fail to assemble P rings, apparently from a similar failure in disulfide bond formation. However, cystine does not completely suppress this defect in dsbA strains. Thus, disulfide bond formation in FlgI is essential for assembly. DsbA likely puts in that bond directly, whereas the DsbB product(s) play a role in oxidizing DsbA, so that it can be active.