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Updated: Nov 3, 2025

Quantification of Bacterial Histidine Kinase Autophosphorylation Using a Nitrocellulose Binding Assay
Published on: January 11, 2017
Nitrate- and Nitrite-Sensing Histidine Kinases: Function, Structure, and Natural Diversity.
Ivan Gushchin1, Vladimir A Aleksenko1, Philipp Orekhov1,2
1Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, 141700 Dolgoprudny, Russia.
Bacteria use nitrate- and nitrite-sensing histidine kinases (NSHKs) to detect electron acceptors. This review details NSHK diversity, structure, and function across various bacterial groups, including those in anaerobic ammonia oxidation communities.
Area of Science:
- Microbiology
- Structural Biology
- Bioinformatics
Background:
- Bacteria utilize nitrates and nitrites as electron acceptors under anaerobic conditions.
- Sensor histidine kinases (HKs) mediate bacterial sensitivity to nitrous compounds.
- Nitrate- and nitrite-sensing HKs (NSHKs), such as NarQ and NarX from *Escherichia coli*, are key regulators.
Purpose of the Study:
- To review the function of NSHKs.
- To analyze the natural diversity of NSHKs.
- To describe the available structural information on NSHKs.
Main Methods:
- Bioinformatic analysis of genomic databases to identify NSHK sequences.
- Comparative analysis of NSHK architecture and domain composition.
- Atomistic modeling to reconcile sequence variations with structural elements.
Main Results:
- Approximately 6000 distinct NSHK sequences were identified, primarily from *Beta-* and *Gammaproteobacteria*, *Bacteroidetes*, and *Chloroflexi*.
- NSHK architecture is largely conserved, though some *Bacteroidetes* proteins lack HAMP/GAF-like domains but may possess PAS domains.
- Structural elements crucial for signal transduction across transmembrane and cytoplasmic regions were identified.
Conclusions:
- NSHKs exhibit significant natural diversity across bacterial phyla.
- Structural variations in NSHKs influence their function in signal transduction.
- Understanding NSHK structure-function relationships is vital for comprehending bacterial anaerobic respiration.
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