| Primary Identifier | IPR020879 | Type | Family |
| Short Name | GlcNAc-bd_A |
| description | This entry represents the N-acetylglucosamine-binding protein A (GbpA) of various pathogenic bacteria, including Vibrio cholerae, which is the etiologic agent of cholera in humans. GbpA binds to chitin and specifically to the chitin monomer N-acetylglucosamine (GlcNAc), a sugar residue that is also found on the surface of epithelial cells. Intestinal colonization of V. cholerae occurs in a stepwise fashion, initiating with attachment to the small intestinal epithelium []. This attachment is followed by expression of the toxin co-regulated pilus, microcolony formation, and cholera toxin production. GlcNAc binding protein A (GbpA) is a secreted attachment factor, which functions in attachment to environmental chitin sources as well as to intestinal substrates. GbpA is expressed and secreted at low-cell densities and is suppressed at high cell-densities and in particular in cells that produced HapR, the central regulator of the cell density dependent quorum sensing system of V. cholerae. HapR activates the expression of genes encoding the secreted proteases HapA and PrtV, which degrade GbpA; suggested that the fluctuation of GbpA levels is a consequence of the levels of bacterial proteases in response to quorum sensing signals. This provides a mechanism for GbpA-mediated attachment to, and detachment from, surfaces in response to environmental cues []. |
