CsgE / CsgF / CsgG - Curli Product Assembly/ Transport Component

β-Barrel Porins

These proteins form transmembrane pores that usually allow the energy independent passage of solutes across a membrane. The transmembrane portions of these proteins consist of β-strands which form a β-barrel. These porin-type proteins are found in the outer membranes of Gram-negative bacteria, mitochondria, plastids and possibly acid-fast Gram-positive bacteria.

95 subfamilies has been described by the Transporter Classification Database (TCDB).

CsgG belongs to the subfamily "The Curli Fiber Subunit, CsgA, Porin, CsgG (CsgG) Family"

CsgG Background Information


Curli are extracellular amyloid fibers produced by enteric bacteria (e.g. Escherichia coli) that are critical for biofilm formation and adhesion to biotic and abiotic surfaces. CsgA and CsgB are the major and minor curli subunits, respectively, while CsgE, CsgF, and CsgG direct the extracellular localization and assembly of curli subunits into fibers
CsgG forms oligomeric pores in the outer membranes of enteric bacteria. Evidence has been presented showing that the CsgA curli subunit is exported across the outer membranes via the CsgG protein.
CsgG forms oligomeric pores in the outer membranes of enteric bacteria. Evidence has been presented showing that the CsgA curli subunit is exported across the outer membranes of enteric bacteria via the CsgG protein.

Data Sheet:


Proteins include but ar not limited to UniProt P0A204 (Salmonella typhimurium); UniProt P0AEA2 (Escherichia coli strain K12); UniProt A8AI45 (Citrobacter koseri)

Function/ Topology:
CsgG forms an oligomeric transport complex composed of nine anticodon-binding-domain-like units that give rise to a 36-stranded β-barrel that traverses the bilayer and is connected to a cage-like vestibule in the periplasm.


Bilayer recordings Orbit instrument family

Reviews and Links


Prof. Dr. Stefan Howorka - Statement about the Orbit 16

Icon Orbit   “Within our research on the CsgG channel, Nanion’s Orbit 16 - combined with Ionera's MECA Chip technology - has substantially boosted our scientific output. The outstanding research tool is easy to handle and speeds up the parallel generation of 16 bilayers. By increasing the throughput of single-channel current recordings, it is a breakthrough in the biophysical analysis of pore forming proteins. Within approximately one week’s worth of lab time, we had the data needed for the recent paper in Nature. This would have been hard to achieve using conventional serial bilayer methods. In addition, the ease-of-use provided by the Orbit 16 shortens the learning curve for making high quality bilayer recordings.  As a benefit in academia, students can now get hands-on experience with bilayer recordings also for shorter projects.“

Dr. Stefan Howorka, Associate Professor of Organic Chemistry and Chemical Biology
University College London, London, UK


2014 - Structural and mechanistic insights into the bacterial amyloid secretion channel CsgG

Icon Orbit  Orbit 16 publication in Nature (2014)

Goyal P., Krasteva P.V., Van GervenN., GubelliniF., Van den BroeckI., Troupiotis-TsaïlakiA., Jonckheere W., Péhau-ArnaudetG., Pinkner J.S., ChapmanM.R., Hultgren S.J., Howorka S., FronzesR., Remaut H.

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