# Characterization of Small Proteins that Regulate Two Component Systems in Escherichia coli

> **NIH NIH FI2** · U.S. NATIONAL INST/CHILD HLTH/HUMAN DEV · 2021 · —

## Abstract

ABSTRACT
Bacteria are ubiquitous and need to survive in numerous environmental conditions. Two component
systems (TCS), which are found in all domains of life and transduce a variety of external and internal
signals into changes in gene expression, are critical to this survival. In the model Gram-negative
organism, Escherichia coli, there are over 20 TCS that are able to respond to different stimuli. These
systems are comprised of at least one sensor histidine kinase at the membrane and one response
regulator, which is generally a transcription factor. These proteins work in coordination to activate a
subset of genes to help ensure survival during specific stressful environments. Small proteins of around
50 amino acids or fewer generally have been overlooked in standard genetic and biochemical
experiments. However, small proteins have been found to regulate a number of responses including
virulence in Salmonella, sporulation in Bacillus subtilis, and the low magnesium induced PhoPQ TCS
in E. coli. The MgrB small protein inhibits the PhoPQ TCS while another small protein, SafA, activates
this TCS. We hypothesize that there are other small proteins in E. coli that also regulate the activities
of TCS. This proposal will use targeted biochemical and global characterization of two candidate small
proteins: YshB and ArcB-C to identify their mechanism of actions. Additionally, a screen will be created
to identify small protein regulators of other TCS systems in E. coli and other bacteria. The results from
this proposal will add to the growing knowledge about small proteins. More broadly, the information
gained from this study could potentially be applied to eukaryotic kinases as they act similarly to bacterial
kinases, which likely are also modulated by small proteins.

## Key facts

- **NIH application ID:** 10271534
- **Project number:** 1FI2GM142815-01
- **Recipient organization:** U.S. NATIONAL INST/CHILD HLTH/HUMAN DEV
- **Principal Investigator:** Aisha Tafa Burton
- **Activity code:** FI2 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** —
- **Award type:** 1
- **Project period:** 2021-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10271534

## Citation

> US National Institutes of Health, RePORTER application 10271534, Characterization of Small Proteins that Regulate Two Component Systems in Escherichia coli (1FI2GM142815-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10271534. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*