Visualizing conformation transitions of the Lipid II flippase MurJ.
Kuk, A.C.Y., Hao, A., Guan, Z., Lee, S.Y.(2019) Nat Commun 10: 1736-1736
- PubMed: 30988294 
- DOI: https://doi.org/10.1038/s41467-019-09658-0
- Primary Citation of Related Structures:  
6NC6, 6NC7, 6NC8, 6NC9 - PubMed Abstract: 
The biosynthesis of many polysaccharides, including bacterial peptidoglycan and eukaryotic N-linked glycans, requires transport of lipid-linked oligosaccharide (LLO) precursors across the membrane by specialized flippases. MurJ is the flippase for the lipid-linked peptidoglycan precursor Lipid II, a key player in bacterial cell wall synthesis, and a target of recently discovered antibacterials. However, the flipping mechanism of LLOs including Lipid II remains poorly understood due to a dearth of structural information. Here we report crystal structures of MurJ captured in inward-closed, inward-open, inward-occluded and outward-facing conformations. Together with mutagenesis studies, we elucidate the conformational transitions in MurJ that mediate lipid flipping, identify the key ion for function, and provide a framework for the development of inhibitors.
Organizational Affiliation: 
Department of Biochemistry, Duke University Medical Center, 303 Research Drive, Durham, NC, 27710, USA.