Biochemistry and Structural Biology of Membrane Protein
Group Leader
The overall objectives of our group are to understand the structural and biochemical underpinnings of membrane transporters and enzymes involved in glycan modification. Using cryo-electron microscopy and protein biochemistry, we aim to capture the mechanisms of action of these biochemical processes, providing fundamental insights to guide the development of new drugs for combating infectious diseases and cancer.
Glycans are remarkably complex in nature and play a critical role in many diseases. Through structural biology, we seek to elucidate the molecular processes that shape them, paving the way for new therapeutic interventions.
Glycans, complex sugars that dominate the surface of nearly every living cell, are essential molecules in the dynamic interplay between our bodies and pathogens. For many pathogens—including fungi, protozoan parasites, and bacteria—attachment to host cell surfaces is the first step in causing disease. In addition to their complexity, subtle changes to glycans, such as the addition or removal of chemical groups, can affect pathogen virulence and the immune response.
Our project aims to understand how certain bacteria modify their cell walls to resist immune responses and antibiotics, and to examine how human cells alter surface sugars, influencing viral infections and cancer cell survival. The project employs state-of-the-art structural biology methods in cryo-electron microscopy (Ung 2022 Nature; Ung 2025 Nature Plants), to capture the mechanisms of action and identify drugs that interfere with these molecular processes. Ultimately, this research could lead to new therapeutic strategies for bacterial infections, viral diseases, and cancers.
Team members
Research Scientists
Kien-Lam UNG
Engineers
Publications
Schulz L*, Ung KL*, et al. Transport of herbicides by PIN-FORMED auxin transporters. Nature Plants (accepted), doi: 10.1101/2024.08.29.610046. [Preprint]
Roth O, Yechezkel S, Serero O, Eliyahu A, Vints I, Tzeela P, Carignano A, Janacek DP, Peters V, Kessel A, Dwivedi V, Carmeli-Weissberg M, Shaya F, Faigenboim-Doron A, Ung KL, Pedersen BP, Riov J, Klavins E, Dawid C, Hammes UZ, Ben-Tal N, Napier R, Sadot E, Weinstain R. Slow release of a synthetic auxin induces formation of adventitious roots in recalcitrant woody plants. Nat Biotechnol 2024 Nov; 42(11):1705-1716.
Ung KL, et al. Substrate recognition and transport mechanism of the PIN-FORMED auxin exporters. Trends Biochem Sci 2023 Nov;48(11):937-948.
Ung KL, et al. Auxin transport at the endoplasmic reticulum: roles and structural similarity of PIN-FORMED and PIN-LIKES. J Exp Bot 2023 Dec 1;74(22):6893-6903.
Ung KL, et al. Structures and mechanism of the plant PIN-FORMED auxin transporter. Nature 2022 Sep;609(7927):605-610.
*Article highlighted in Nature Plants: Tena, G. PIN finally up. Nat. Plants 8, 725 (2022).
*Research highlight of the year by the Electron Bio-Imaging Centre (eBIC-2023)
Alsarraf HMAB, Ung KL, et al. Biochemical, structural, and functional studies reveal that MAB_4324c from Mycobacterium abscessus is an active tandem repeat N-acetyltransferase. FEBS Lett 2022 Jun;596(12):1516-1532.
Ung KL, et al. MmpL3, the trehalose monomycolate transporter, is stable in solution in several detergents and can be reconstituted into peptidiscs. Protein Expr Purif 2022 Mar;191:106014.
Ung KL, et al. Structural analysis of the N-acetyltransferase Eis1 from Mycobacterium abscessus reveals the molecular determinants of its incapacity to modify aminoglycosides. Proteins 2021 Jan;89(1):94-106.
Ung KL, et al. The crystal structure of the mycobacterial trehalose monomycolate transport factor A, TtfA, reveals an atypical fold. Proteins 2020 Jun;88(6):809-815.
Ung KL, et al. Crystal structure of the aminoglycosides N-acetyltransferase Eis2 from Mycobacterium abscessus. FEBS J 2019 Nov;286(21):4342-4355.
Collaboration & Funding
The team is supported by a starting grant from the Fondation pour la Recherche Médicale (2025-2028), «Amorçage de Jeunes Équipes » program
Prizes
- « Article of the month 2023 » – Société Française de Biochimie et Biologie Moléculaire
Ung, KL et al., Nature Sep;609(7927):605-610 (2022). - « Article of the year – 2023 » – Société Française de Biochimie et Biologie Moléculaire
Ung, KL et al., Nature Sep;609(7927):605-610 (2022).