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Whole membrane proteome for depletion of Bam subunits in F. johnsoniae

ABSTRACT: In Gram-negative bacteria the outer membrane (OM) is the first line of defence against antimicrobial agents and immunological attacks. A key part of OM biogenesis is the insertion of OM proteins (OMPs) by the β-barrel–assembly machinery (BAM). Here we report the cryo-electron microscopy (cryoEM) structure of a BAM complex isolated from Flavobacterium johnsoniae, a member of the Bacteroidota, a phylum that includes key human commensals and major anaerobic pathogens. This BAM complex is extensively modified from the canonical Escherichia coli system and includes an extracellular canopy that overhangs the substrate folding site and a subunit that inserts into the BAM pore. We find that the novel subunits involved in forming the extracellular canopy, BamG and BamH, are required for BAM function and conserved across the Bacteroidota, suggesting that they form an essential extension to the canonical BAM core in this phylum. For BamH, isolation of a suppressor mutation allows the separation of its essential and non-essential functions. The need for a highly remodelled and enhanced BAM complex reflects the unusually complex membrane proteins found in the OM of the Bacteroidota.

INSTRUMENT(S):

ORGANISM(S): Flavobacterium Johnsoniae Uw101

SUBMITTER: Vaishnavi Ravikumar

LAB HEAD: Marjorie Fournier

PROVIDER: PXD065907 | Pride | 2025-08-04

REPOSITORIES: Pride

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			Action	DRS
	QEX03_VR_240806_LOT_11_038.raw	Raw
	QEX03_VR_240806_LOT_12_040.raw	Raw
	QEX03_VR_240806_LOT_13_042.raw	Raw
	QEX03_VR_240806_LOT_14_044.raw	Raw
	QEX03_VR_240806_LOT_15_046.raw	Raw

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