Alpha-like protein Rib, N-terminal domain (Rib-N)

The Alpha-like protein Rib is a prominent surface-anchored protein found in Group B Streptococcus (GBS), particularly associated with highly virulent strains such as those belonging to serotype III (UniProt P72444). It belongs to the Alpha-like protein (Alp) family, characterized by a structural organization consisting of a unique N-terminal domain, a series of identical tandem repeats, and a C-terminal LPXTG cell wall anchoring motif (PubMed: 21844305). The N-terminal domain of Rib is a critical target for vaccine development because it is highly immunogenic, surface-exposed, and relatively conserved among Rib-expressing strains (PubMed: 25644012). In the context of infection, Rib facilitates immune evasion and bacterial persistence within the host by interfering with the immune response. Therapeutic strategies, such as the GBS-NN vaccine candidate, utilize the N-terminal domains of Rib and other Alp proteins to elicit protective opsonophagocytic antibodies in pregnant women (Minervax). These antibodies are intended to be transferred to the fetus to provide passive immunity against neonatal sepsis, meningitis, and pneumonia caused by GBS.

Other names

Rib protein N-terminal domainSurface protein Rib N-terminusR-domain of RibGroup B Streptococcus Rib proteinAlp family protein Rib

Induction of protective opsonophagocytic antibodies (OPA) that target the surface-exposed N-terminal domain to facilitate bacterial clearance by the host immune system.