Touati E, Dassa E, Dassa J, Boquet P L, Touati D
Service de Biochimie des Protéines, CEN Saclay, Gif-sur-Yvette, France.
Res Microbiol. 1991 Jan;142(1):29-36. doi: 10.1016/0923-2508(91)90094-q.
The phenotype of Escherichia coli appR pleiotropic mutants has been compared with that of mutants in the katF gene, which lies in the same region and controls expression of catalase HPII (katE) and exonuclease III (xth). All the described characters of appR mutants--reduced pH 2.5 acid phosphatase level, overexpression of alkaline phosphatase and ability of crp or cya mutants to utilize some CAP + cAMP-dependent carbon sources--were reproduced by a katF:: Tn10 insertion. In all cases, the wild-type phenotype was restored by the presence of a plasmid-borne katF+ gene. Conversely, spontaneous appR mutants were hypersensitive to H2O2 to the same degree as katF mutants. We conclude that the appR gene is identical to katF, which encodes a putative new sigma factor (Mulvey and Loewen, 1989).
已将大肠杆菌appR多效突变体的表型与katF基因的突变体表型进行了比较，katF基因位于同一区域，控制过氧化氢酶HPII（katE）和核酸外切酶III（xth）的表达。appR突变体的所有已描述特征——pH 2.5酸性磷酸酶水平降低、碱性磷酸酶过表达以及crp或cya突变体利用某些CAP + cAMP依赖性碳源的能力——都可通过katF::Tn10插入来重现。在所有情况下，质粒携带的katF+基因的存在可恢复野生型表型。相反，自发的appR突变体对H2O2的敏感性与katF突变体相同。我们得出结论，appR基因与katF基因相同，katF基因编码一种假定的新的σ因子（Mulvey和Loewen，1989）。
