# Structure and function of a metabolic pacemaker in bacterial cell membrane

> **NIH NIH R01** · UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON · 2021 · $319,800

## Abstract

Abstract
Glycolysis constitutes one of the most important metabolic pathways conserved in both eukaryotes and
prokaryotes. In the pathway, glucose is broken down to form small 3-carbon phosphate metabolites essential for
cell growth and survival. In microorganisms, properly maintaining glycolysis is important for the development of
bacterial infection and virulence and antibiotic resistance. In this project, we aim to study the structure and
function of phosphatidylglycerol phosphatase PgpA to elucidate a novel regulatory mechanism of glycolysis in
bacterium. PgpA is an integral membrane protein ubiquitously found in Gram-negative bacterium. We found that
PgpA functions as a moonlighting enzyme; i.e. PgpA is not only involved in phospholipid biosynthesis but also
acts as an essential metabolic regulator by hydrolyzing the key 3-carbon phosphate glycolytic metabolites in E.
coli. Mutational inactivation of PgpA in E. coli greatly facilitates bacterial metabolism and growth. We have also
identified a novel redox-regulatory mechanism of PgpA, which is important to maintain bacterial metabolic
homeostasis. Our findings raise the hypothesis for a redox-mediated regulatory mechanism in which PgpA
regulates bacterial glycolysis by controlling glutathione-mediated redox balance based on external and internal
metabolic signals. This regulatory mechanism is novel and has not yet been reported in any cell type. To further
understand this regulatory mechanism, we will study how PgpA controls bacterial glucose uptake and regulate
glycolytic activity using a combination of biochemistry, microbiology, and metabolomic approaches.To
understand how PgpA regulates intracellular redox balance, we will examine glutathione biosynthesis and
monitor redox changes on the membrane surface of PgpA to demonstrate how PgpA uses an integrative “Ying-
Yang” mechanism to achieve both metabolic homeostasis and redox balance. We also found the redox-mediated
regulation of PgpA is mediated by dimeric disulfide crosslinking within PgpA dimer. To gain structural insights
into this novel redox-regulated catalytic mechanism, we will study the catalytic activity of PgpA and co-factor
Mg2+ binding in response to redox changes in vitro using biochemical assays. We will also study this molecular
mechanism using FRET to demonstrate how dimeric crosslinking alters protein conformation to allosterically
change the active site conformation in order to control the PgpA catalysis. Since no structure is available in the
PgpA family, we will determine the structures of PgpA in two distinct redox (active/inactivated) states using the
X-ray crystallography and single-particle cryoEM approaches to establish a structural basis for the redox-
regulated catalytic mechanism of PgpA. This mechanism is conserved in many Gram-negative pathogens. Our
studies will reveal an important mechanism to understand metabolic regulation in microorganisms.

## Key facts

- **NIH application ID:** 10280369
- **Project number:** 1R01GM143418-01
- **Recipient organization:** UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
- **Principal Investigator:** Lei Zheng
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $319,800
- **Award type:** 1
- **Project period:** 2021-08-01 → 2025-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10280369

## Citation

> US National Institutes of Health, RePORTER application 10280369, Structure and function of a metabolic pacemaker in bacterial cell membrane (1R01GM143418-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10280369. Licensed CC0.

---

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