σ^(38)和RMF对有关基因表达调控的研究

STUDIES ON MODULATION AND CONTROL OF σ^(38) AND RMF FOR THE EXPRESSION OF SOME GENES

将大肠杆菌的rpoS和rmf基因突变型和野生型菌株分别培养在营养丰富的LB培养基和成分有限的EP培养基上。在相同条件下,进入稳定期后的突变型菌株的活细胞数低于野生菌株。采用 Western blot方法测定了不同基因产物在稳定期的变化。σ^(38)对RNA聚合酶核心酶亚单位结构基因 rpoA、rpoB、rpoC以及groEs和tufA基因的表达影响不大,能抑制crp和促进rmf的表达。RMF在营养丰富的条件下对rpoA、rpoD,groEl、rho、tufA和ompA基因的表达有促进作用,而在EP条件下的影响并不明显,对crp和rpoS的表达分别有抑制和促进作用。

The E.coli mutants and wild type strains of rpoS and rmf were cultured in rich medium LB and limited component medium EP respectively. During the stationary phase, the viable cells of mutants were less than wild type strains's. The change of the product of serial proteins was quantified with Western blot. σ38 has no effects on the product of rpoA, rpoB, rpoC, groE and tu gene, depress the transcription of crp and promote the expression of rmf. RMF can promote expression of rpoA, rpoD, groE1, rho, ompA and tufA gene in rich medium, but not in limited medium, and then depress and promote the expression of crp and rpoS respectively.