1.D.282.  The 280 kDa, 18 subunit Pore-forming Complex (PfC:CsgFG) Family 

SuFEx chemistry has been used to covalently stabilize an 18-subunit pore-forming complex, CsgG:CsgF, consisting of nine CsgG membrane protein subunits that noncovalently associate with nine CsgF peptides. Derivatives of the CsgG:CsgF pore have been used for DNA sequencing, which places high demands on the structural stability and homogeneity of the complex. To increase the robustness of the pore, Schnaider et al. 2024 designed and synthesized derivatives of CsgF-bearing sulfonyl fluorides, which react with CsgG in high yield to form a covalently stabilized CsgG:CsgF complex. The resulting pores formed highly homogeneous channels when added to artificial membranes. The high yield and rapid reaction rate of the SuFEx reaction prompted molecular dynamics simulations, which revealed that the SO₂F groups in the initially formed complex are poised for nucleophilic reaction with a targeted Tyr. This demonstrates the utility of SuFEx chemistry to structurally stabilize very large assemblies (Schnaider et al. 2024).