9G9M

Lipid III flippase WzxE with NB10 and NB7 nanobodies in outward-facing conformation - crystal 1

Summary for 9G9M

• Entry DOI: 10.2210/pdb9g9m/pdb
• Related: 9G95 9G97
• Descriptor: Lipid III flippase, NB10 Nanobody, NB7 Nanobody, ... (5 entities in total)
• Functional Keywords: membrane protein, flippase, cell wall, enterobacterial common antigen, lipid iii, transport protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 3
• Total formula weight: 76582.23

Authors

Le Bas, A.,Naismith, J.H. (deposition date: 2024-07-25, release date: 2025-01-22)

Primary citation

Le Bas, A.,Clarke, B.R.,Teelucksingh, T.,Lee, M.,El Omari, K.,Giltrap, A.M.,McMahon, S.A.,Liu, H.,Beale, J.H.,Mykhaylyk, V.,Duman, R.,Paterson, N.G.,Ward, P.N.,Harrison, P.J.,Weckener, M.,Pardon, E.,Steyaert, J.,Liu, H.,Quigley, A.,Davis, B.G.,Wagner, A.,Whitfield, C.,Naismith, J.H.
Structure of WzxE the lipid III flippase for Enterobacterial Common Antigen polysaccharide.
Open Biology, 15:240310-240310, 2025

PubMed Abstract: The enterobacterial common antigen (ECA) is conserved in Gram-negative bacteria of the order although its function is debated. ECA biogenesis depends on the Wzx/Wzy-dependent strategy whereby the newly synthesized lipid-linked repeat units, lipid III, are transferred across the inner membrane by the lipid III flippase WzxE. WzxE is part of the Wzx family and required in many glycan assembly systems, but an understanding of its molecular mechanism is hindered due to a lack of structural evidence. Here, we present the first X-ray structures of WzxE from in complex with nanobodies. Both inward- and outward-facing conformations highlight two pairs of arginine residues that move in a reciprocal fashion, enabling flipping. One of the arginine pairs coordinated to a glutamate residue is essential for activity along with the C-terminal arginine rich tail located close to the entrance of the lumen. This work helps understand the translocation mechanism of the Wzx flippase family.

PubMed: 39772807
DOI: 10.1098/rsob.240310

Experimental method

X-RAY DIFFRACTION (2.55 Å)