Group B Streptococcus alpha-like surface protein αC N-terminal domain (NtACP)

The Group B Streptococcus (GBS) alpha-like surface protein αC N-terminal domain (NtACP) is a critical virulence factor and a primary target for vaccine development against GBS infections (Aupérin et al., 2005). As the archetype of the alpha-like protein (Alp) family, NtACP functions as an invasin, mediating the internalization and translocation of the bacterium across human epithelial barriers, such as the cervix and placenta (Bolduc et al., 2002). Structurally, the domain consists of a beta-sandwich (D1) with an integrin-binding KTD motif and a three-helix bundle (D2) involved in glycosaminoglycan binding (Aupérin et al., 2005; Baron et al., 2004). By interacting with host cell receptors like alpha1beta1-integrin and heparin, NtACP facilitates the entry of GBS into host cells, contributing to diseases such as neonatal sepsis, meningitis, and pneumonia (Fischer et al., 2021; Bolduc et al., 2002). Therapeutic strategies, most notably the GBS-NN subunit vaccine, utilize the N-terminal domains of Alpha C and Rib proteins to elicit protective IgG antibodies (Pawlowski et al., 2022). These antibodies provide immunity by promoting opsonophagocytic killing and blocking the protein's ability to mediate host cell invasion (Fischer et al., 2021; Pawlowski et al., 2022).

Other names

Alpha C protein N-terminal domainACP N-terminal domainbca gene product N-terminal domainAlp-NC-alpha protein N-terminal domain

Induction of protective IgG antibodies that promote opsonophagocytic killing and inhibit bacterial invasion of host epithelial cells.