1.B.35.2.1
The N-acetylneuraminic acid-inducible, anion selective porin, NanC (Condemine et al., 2005). A crystal structure (3.3 Å resolution) is available (2WJQ; Wirth et al., 2009). It forms a 28 Å high 12 stranded β barrel like the autotransporter, NalP. The pore is lined by basic residues (conserved in other KdgM family members) allowing diffusion of acidic oligosaccharides (Wirth et al., 2009).  Single channels of NanC at pH 7.0 have: (1) conductance 100 to 800 pS in 100 mM: KCl to 3 M: KCl), (2) anion over cation selectivity, and (3) two forms of voltage-dependent gating (channel closures above 200 mV). Phosphate interferes with channel conductance (Giri et al. 2012).