This domain is found in CofB from Escherichia coli and in similar proteins predominantly from proteobacteria. CofB is a minor pilin, required for assembly of Type IV pili. This entry represents the pilin domain, which is located in the N-terminal region of the protein. It shows a canonical T4b pilin fold seen in the major pilins, with an alpha-helical backbone and a five-stranded anti- parallel beta-sheet [1,2].

1: Crystal Structure of the Minor Pilin CofB, the Initiator of CFA/III Pilus Assembly in Enterotoxigenic Escherichia coli. Kolappan S, Ng D, Yang G, Harn T, Craig L; J Biol Chem. 2015;290:25805-25818. PMID:26324721

2: Homo-trimeric Structure of the Type IVb Minor Pilin CofB Suggests Mechanism of CFA/III Pilus Assembly in Human Enterotoxigenic Escherichia coli. Kawahara K, Oki H, Fukakusa S, Yoshida T, Imai T, Maruno T, Kobayashi Y, Motooka D, Iida T, Ohkubo T, Nakamura S; J Mol Biol. 2016;428:1209-1226. PMID:26876601