YdfH identified as a repressor of rspA by the use of reduced genome Escherichia coli MGF-01

Biosci Biotechnol Biochem. 2012;76(9):1688-93. doi: 10.1271/bbb.120273. Epub 2012 Sep 7.


We have reported the construction of 1 Mb reduced genome Escherichia coli MGF-01 by a 28-step operation. This time, transcriptome analysis of MGF-01 was performed. Although the transcriptome profiles of the exponential phase in parental strain W3110red were well-conserved in MGF-01, the rspAB operon was highly expressed. A LacZ reporter assay of a series of stepwise deletion strains prepared in the course of MGF-01 construction indicated that rspA was highly expressed after the 5th step. Further analysis indicated that Δ29, one of the deleted regions at the 5th step, relates to an increase in rspA expression, and that transcriptional regulator ydfH, in the Δ29 region, is responsible for the expression of rspA, gel shift assay indicated that YdfH bound directly to the upstream region of rspA. Based on these results, it was concluded that YdfH is a transcriptional repressor of the rspAB operon.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Escherichia coli / genetics*
  • Escherichia coli Proteins / genetics*
  • Escherichia coli Proteins / metabolism
  • Gene Deletion
  • Gene Expression Regulation, Bacterial*
  • Genes, Reporter
  • Genetic Engineering
  • Genome Size
  • Genome, Bacterial*
  • Lac Operon
  • Operon*
  • Protein Binding
  • Repressor Proteins / genetics*
  • Repressor Proteins / metabolism
  • Transcriptome*


  • Escherichia coli Proteins
  • Repressor Proteins
  • YdfH protein, E coli
  • rspA protein, E coli