Valley Stewart

Valley Stewart

Position Title

Department of Microbiology and Molecular Genetics

239A Briggs Hall

Research Interests

Completed Research Projects

Physiology and regulation of anaerobic resipiration in Escherichia coli (supported by NIGMS)

Phosphatase mechanism and function in two-component signal transduction (supported by NIGMS)

Nitrogen assimilation by Klebsiella oxytoca (supported by DOE)

Hyper-encapsulation by invasive Klebsiella pneumoniae (supported by NIAID)

Regulation of denitrification in Pseudomonas aeruginosa (supported by NIAID)

Signaling in bacterium-plant interactions

I currently am a sabbatical leave visitor in the laboratory of Prof. Pamela Ronald (UC Davis), who studies the control of innate immune response by rice (Oryzae sativa) to Xanthomonas oryzae.  This bacterium causes economically significant diseases in an agricultural staple that also is a model for broadly understanding cereal genetics.  Our goal is to integrate analyses of both pathogen and host as we seek to understand plant resistance.


  • MIC 102 Introductory Microbiology
  • MIC 111 Human Microbiology
  • MIC 150 Genomes of Pathogenic Bacteria


  • 1982 PhD Microbiology University of Virginia
  • 1977 BA Biology University of Colorado


Boudes, M., N. Lazar, M. Graille, D. Durand, T. A. Gaidenko, V. Stewart, and H. van Tilbeurgh.  2012.  The structure of the NasR transcription antiterminator reveals a one-component system with a NIT nitrate receptor coupled to an ANTAR RNA-binding effector.  Mol. Microbiol. 85: 431-444.  PMID: 22690729

Huynh, T. N., C. E. Noriega, and V. Stewart.  2013.  Missense substitutions reflecting regulatory control of transmitter phosphatase activity in two-component signaling.  Mol. Microbiol. 88:459-472.  PMCID: PMC3633741

Huynh, T. N., L.-L. Chen, and V. Stewart.  2015.  Sensor–response regulator interactions in a cross-regulated signal transduction network.  Microbiology 161:1504-1515.  PMID: 25873583

Huynh, T. N., H.-Y. Lin, C. E. Noriega, A. V. Lin, and V. Stewart.  2015.  Crosstalk Inhibition Nullified by a Receiver Domain Missense Substitution.  J. Bacteriol. 197: 3294-3306.  PMID: 26260457