# Structural and functional characterization of phosphoglycosyl transferases from human pathogens

> **NIH NIH F32** · MASSACHUSETTS INSTITUTE OF TECHNOLOGY · 2020 · $65,310

## Abstract

Abstract:
 This project aims to expand the mechanistic understanding of the initial membrane-associated steps of
bacterial glycoconjugate biosynthesis. Membrane protein structures are critically underrepresented in the
protein data bank (PDB), and remain difficult targets for purification, characterization and mechanistic analysis.
The products of these biosynthetic pathways are required for both bacterial viability and virulence and are
attractive targets for antimicrobial design. Examples include capsular polysaccharide (CPS), cell wall teichoic
acid, lipopolysaccharide (LPS) and N- and O-linked glycoproteins.
The first membrane-bound step of glycoconjugate biosynthesis is catalyzed by phosphoglycosyl transferases
(PGTs). This class of enzymes transfers a sugar from an NDP-sugar onto an undecaprenyl phosphate lipid
anchor. Different PGTs exhibit different substrate selectivity, the molecular determinants of which remain
unknown. The first structure of a PGT, PglC from Campylobacter concisus was solved recently, but crystallized
in a conformation in which the active site is open and unliganded.
Both Styrene maleic acid copolymer (SMALP) and traditional detergents will be used to solubilize and purify
PGTs of differing substrate selectivity. Chemoenzymatic synthesis will be used to generate UDP-sugar
substrates for PGTs such as UDP-diNAcBac and UDP-fucose. A rapid, luminescence-based assay will be
used to characterize solubilized targets and synthesized substrates. Lipid cubic phase (LCP) methods will
facilitate crystallization of SMALP solubilized targets that have never left a lipid bilayer. Synthetic substrates
will be utilized for soaking or cocrystallization experiments. These experiments will broaden our understanding
of PGT structure-function relationships. Data will also inform efforts to develop inhibitors, as PGTs remain an
underexplored area for the development of antimicrobial and antivirulence agents.

## Key facts

- **NIH application ID:** 10001977
- **Project number:** 5F32GM134576-02
- **Recipient organization:** MASSACHUSETTS INSTITUTE OF TECHNOLOGY
- **Principal Investigator:** Gregory J Dodge
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $65,310
- **Award type:** 5
- **Project period:** 2019-09-01 → 2022-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10001977

## Citation

> US National Institutes of Health, RePORTER application 10001977, Structural and functional characterization of phosphoglycosyl transferases from human pathogens (5F32GM134576-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10001977. Licensed CC0.

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