Defining the remarkable structural malleability of a bacterial surface protein Rib domain implicated in infection

摘要: Streptococcus groups A and B cause serious infections, including early onset sepsis meningitis in newborns. Rib domain-containing surface proteins are found associated with invasive strains elicit protective immunity animal models. Yet, despite their apparent importance infection, the structure of domain was previously unknown. Structures single domains differing length reveal a rare case atrophy through deletion 2 core antiparallel strands, resulting loss an entire sheet β-sandwich from immunoglobulin-like fold. Previously, observed variation number within these bacterial cell wall-attached has been suggested as mechanism immune evasion. Here, tandem domains, combined molecular dynamics simulations small angle X-ray scattering, suggests that variability would result differential projection N-terminal host-colonization surface. The identification further structures where typical B-D-E immunoglobulin β-sheet is replaced α-helix confirms extensive structural malleability domain.