title: A novel endogenous induction of ColE7 expression in a csrA mutant of Escherichia coli.
abstract: Carbon storage regulator A (CsrA) is an important regulator that controls central metabolic pathways and a variety of physiological functions. We found that disruption of csrA in cells containing the ColE7 operon caused a 12-fold increase in colicin E7 production. Moreover, real-time RT-PCR demonstrated a decrease of around 50 % in the lexA mRNA of the csrA mutant. However, the cellular level of RecA protein and its mRNA were not significantly different from the wild type strain. Our results suggest that a novel induction mechanism might exist in E. coli that allows the expression of ColE7 operon in response to a metabolic shift. Proteomic analysis suggested that csrA deficient mutant may adapt PEP-glyoxylate cycle for energy production. Thus, the physiological changes in the csrA mutant may be similar to carbon source limitation for initiating the expression of ColE7 operon in response to stringent environmental conditions.
authors.affiliation: Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, 11221, Taiwan.
authors.forename: Hao-Wei
authors.initials: HW
authors.lastname: Chang
authors.forename: Tsung-Yeh
authors.initials: TY
authors.lastname: Yang
authors.forename: Guang-Sheng
authors.initials: GS
authors.lastname: Lei
authors.forename: Kin-Fu
authors.initials: KF
authors.lastname: Chak
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis; D002244:Carbon / Q000378:metabolism; D003087:Colicins / Q000096:biosynthesis*; D004734:Energy Metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000235:genetics; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D055786:Gene Knockout Techniques; D020543:Proteome / Q000032:analysis; D016601:RNA-Binding Proteins / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D011938:Rec A Recombinases / Q000096:biosynthesis; D012097:Repressor Proteins / Q000172:deficiency* / Q000235:genetics; D012697:Serine Endopeptidases / Q000096:biosynthesis; D000099160:LexA Repressor Protein
chemical_list: D001426:Bacterial Proteins; D002244:Carbon; D003087:Colicins; D029968:Escherichia coli Proteins; D020543:Proteome; D016601:RNA-Binding Proteins; D011938:Rec A Recombinases; D012097:Repressor Proteins; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein; C508089:ColE7 protein, E coli; C093587:CsrA protein, E coli