A mutational study of the ArcA-P binding sequences in the aldA promoter of Escherichia coli

M. Teresa Pellicer, A. S. Lynch, P. De Wulf, D. Boyd, Juan Aguilar, E. C C Lin

Research output: Contribution to journalArticlepeer-review

Abstract

The aldA gene (encoding aldehyde dehydrogenase) of Escherichia coli is anaerobically repressed by ArcA-P, the phosphorylated response regulator of the ArcB/A two-component signal transduction system. The promoter region of aldA contains two 10-bp sequences (5'-TGTTAATTAA-3') that perfectly match the proposed ArcA-P binding consensus (5'-[A/T]GTTAATTA[A/T]-3'). One consensus sequence is on the coding strand (-13 to -4 from the transcriptional start point), whereas the other is on the template strand (position -2 to -11). In this study we used the aldA promoter to test the validity of the proposed consensus sequence. DNase I protection experiments confirmed the 10-bp sequence to be a strong ArcA-P binding site. Alteration of the wild-type sequence from 5'-TGTTAATTAAC-3' to 5'-TCTTAATTAAG-3' or 5'-TATTAATTAAT-3' by site-directed mutagenesis markedly decreased the in vitro affinity of the promoter region for ArcA-P, and abolished the anaerobic repression of mutant attλ::Φ (aldA'-lacZ) transcriptional reporter constructs. Both the in vitro and in vivo results therefore support the proposed consensus sequence.

Original languageEnglish
Pages (from-to)170-176
Number of pages7
JournalMGG Molecular & General Genetics
Volume261
Issue number1
DOIs
Publication statusPublished - 1999

Keywords

  • Aldehyde dehydrogenase
  • Arc two-component system
  • Escherichia coli
  • Signal transduction

ASJC Scopus subject areas

  • Genetics
  • Molecular Biology

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