Direct linking of metabolism and gene expression in the proline utilization A protein from Escherichia coli

Yuzhen Zhou, Weidong Zhu, Padmanetra S. Bellur, Dustin Rewinkel, Donald F. Becker

Research output: Contribution to journalReview article

28 Scopus citations


The control of gene expression by enzymes provides a direct pathway for cells to respond to fluctuations in metabolites and nutrients. One example is the proline utilization A (PutA) protein from Escherichia coli. PutA is a membrane-associated enzyme that catalyzes the oxidation of l-proline to glutamate using a flavin containing proline dehydrogenase domain and a NAD + dependent Δ1-pyrroline-5-carboxylate dehydrogenase domain. In some Gram-negative bacteria such as E. coli, PutA is also endowed with a ribbon-helix-helix DNA-binding domain and acts as a transcriptional repressor of the proline utilization genes. PutA switches between transcriptional repressor and enzymatic functions in response to proline availability. Molecular insights into the redox-based mechanism of PutA functional switching from recent studies are reviewed. In addition, new results from cell-based transcription assays are presented which correlate PutA membrane localization with put gene expression levels. General membrane localization of PutA, however, is not sufficient to activate the put genes.

Original languageEnglish (US)
Pages (from-to)711-718
Number of pages8
JournalAmino Acids
Issue number4
StatePublished - Nov 1 2008



  • DNA-binding
  • Membrane-binding
  • Multifunctional enzyme
  • Proline utilization
  • PutA
  • Transcriptional regulation

ASJC Scopus subject areas

  • Biochemistry
  • Clinical Biochemistry
  • Organic Chemistry

Cite this