This is the C-terminal domain found in hemagglutinin component such as HA70 found in Clostridium botulinum. HA is a component of the large botulinum neurotoxin complex and is critical for its oral toxicity. HA plays multiple roles in toxin penetratio ...
This is the C-terminal domain found in hemagglutinin component such as HA70 found in Clostridium botulinum. HA is a component of the large botulinum neurotoxin complex and is critical for its oral toxicity. HA plays multiple roles in toxin penetration in the gastrointestinal tract, including protection from the digestive environment, binding to the intestinal mucosal surface, and disruption of the epithelial barrier [1]. HA consists of three different proteins, designated HA70 (also known as HA3), HA33 (HA1), and HA17 (HA2) based on molecular mass [2]. HA70 consists of three domains (D1-3). The D1 and D2 domains, which adopt similar structures, mediate the trimerization of HA70 with each protomer. The D3 domain, sitting at the tip of the trimer, is composed of two similar jelly-roll-like beta-sandwich structures [3]. Furthermore, crystal structures of HA70 in a complex with alpha2,3- or alpha2,6-SiaLac (alpha2,6-sialyllactose), show that alpha2,3- and alpha2,6-SiaLac bound to the same region in the D3 domain of HA70. This domain is the D3 domain found in HA3/HA70 which has been shown to be involved in binding to carbohydrate of glycoproteins from epithelial cells in the infection process [2].
