Fig. 8: Proposed depiction of the role of GlpG in maintaining protein quality control of FimA for the proper assembly of type 1 pili in E. coli.
From: Rhomboid protease GlpG regulates type 1 pili quality control and virulence in pathogenic E. coli
GlpG (blue) is closely associated with members of the SecYEG translocon (green) as well as other resident proteases in the periplasm, such as DegQ and DegP (grey), to readily prevent and clear FimA (yellow) aggregates. When FimC chaperone (purple) is not available to bind FimA, GlpG cleaves FimA at its hydrophobic C-terminal tail to facilitate its clearance and prevent the aggregation of FimA in the periplasm. The remainder of the FimA molecule is degraded by housekeeping proteases that cleave misfolded proteins in the periplasm, such as DegP and DegQ. Loss of GlpG catalytic activity causes the accumulation of FimA aggregates and impaired type 1 pili formation, which in turn affects host colonization of E. coli. Created with BioRender.com. https://BioRender.com/xstqntw.
