title: The promoter of the tgt/sec operon in Escherichia coli is preceded by an upstream activation sequence that contains a high affinity FIS binding site.
abstract: The tgt/sec operon in E. coli consists of five genes: queA, tgt, ORF12, secD, and secF. QueA and Tgt participate in the biosynthesis of the hypermodified t-RNA nucleoside Queuosine, whereas SecD and SecF are involved in protein secretion. Examination of the promoter region of the operon showed structural similarity to promoter regions of the rrn-operons. An upstream activation sequence (UAS) containing a potential binding site for the factor of inversion stimulation (FIS) was found. Gel retardation assays and DNaseI footprinting indicated, that FIS binds specifically and with high affinity to a site centred at position -58. Binding of FIS caused bending of the DNA, as deduced from circular permutation analysis. Various 5' deletion mutants of the promoter region were constructed and fused to a lacZ reporter gene to determine the influence of the UAS element on the promoter strength. An approximately two-fold activation of the promoter by the UAS element was observed.
authors.affiliation: Institut für Biochemie, Universität Erlangen-Nürnberg, Germany.
authors.forename: R K
authors.initials: RK
authors.lastname: Slany
authors.forename: H
authors.initials: H
authors.lastname: Kersten
mesh_terms: D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics*; D002352:Carrier Proteins / Q000235:genetics*; D016384:Consensus Sequence / Q000235:genetics; D004252:DNA Mutational Analysis; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; D034982:Integration Host Factors; D008969:Molecular Sequence Data; D009704:Nucleoside Q / Q000235:genetics; D009876:Operon / Q000235:genetics; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011993:Recombinant Fusion Proteins / Q000235:genetics
chemical_list: D002352:Carrier Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; D035021:Factor For Inversion Stimulation Protein; D034982:Integration Host Factors; D011993:Recombinant Fusion Proteins; C440502:integration host factor, E coli; D009704:Nucleoside Q