Colonization factor antigen I major fimbrial subunit (CfaB) (CfaB)

Colonization factor antigen I (CFA/I) major fimbrial subunit, also known as CfaB, is the principal protein component of CFA/I fimbriae produced by enterotoxigenic Escherichia coli (ETEC). Each CFA/I fimbria consists of around 1,000 copies of CfaB arranged in a helical filament, forming the stalk structure that extends from the bacterium’s surface. The primary biological role of CfaB is to mediate the attachment of ETEC to the human intestinal mucosa, facilitating colonization and subsequent delivery of enterotoxins. CfaB assembles as a polymer and supports a minor tip adhesin subunit (CfaE) that directly interacts with host cell receptors[1][2][3]. Disruption of CfaB expression or assembly significantly impairs ETEC adherence, making CfaB and the CFA/I fimbria essential for ETEC pathogenesis and a target for vaccine development, though not a conventional small-molecule drug target.

Other names

CfaBCFA/I major pilinCFA/I major fimbrial subunitMajor structural subunit of CFA/ICFA/I stalk protein

When used as a vaccine antigen, the mechanism is induction of anti-adhesion antibodies that block ETEC colonization