7T6D

CryoEM structure of the YejM/LapB complex

Summary for 7T6D

• Entry DOI: 10.2210/pdb7t6d/pdb
• EMDB information: 25713
• Descriptor: Lipopolysaccharide assembly protein B, Inner membrane protein YejM, 2-(HEXADECANOYLOXY)-1-[(PHOSPHONOOXY)METHYL]ETHYL HEXADECANOATE, ... (4 entities in total)
• Functional Keywords: yejm, ycim, regulation, lipopolysaccharide synthesis, lpxc, membrane protein
• Biological source: Escherichia coli; More
• Total number of polymer chains: 4
• Total formula weight: 227221.16

Authors

Mi, W.,Shu, S. (deposition date: 2021-12-13, release date: 2022-08-17, Last modification date: 2024-02-28)

Primary citation

Shu, S.,Mi, W.
Regulatory mechanisms of lipopolysaccharide synthesis in Escherichia coli.
Nat Commun, 13:4576-4576, 2022

PubMed Abstract: Lipopolysaccharide (LPS) is an essential glycolipid and forms a protective permeability barrier for most Gram-negative bacteria. In E. coli, LPS levels are under feedback control, achieved by FtsH-mediated degradation of LpxC, which catalyzes the first committed step in LPS synthesis. FtsH is a membrane-bound AAA+ protease, and its protease activity toward LpxC is regulated by essential membrane proteins LapB and YejM. However, the regulatory mechanisms are elusive. We establish an in vitro assay to analyze the kinetics of LpxC degradation and demonstrate that LapB is an adaptor protein that utilizes its transmembrane helix to interact with FtsH and its cytoplasmic domains to recruit LpxC. Our YejM/LapB complex structure reveals that YejM is an anti-adaptor protein, competing with FtsH for LapB to inhibit LpxC degradation. Structural analysis unravels that LapB and LPS have overlapping binding sites in YejM. Thus, LPS levels control formation of the YejM/LapB complex to determine LpxC protein levels.

PubMed: 35931690
DOI: 10.1038/s41467-022-32277-1

Experimental method

ELECTRON MICROSCOPY (3.9 Å)