3qq2 | pdb_00003qq2
Crystal Structure of the Beta Domain of the Bordetella Autotransporter Brka
Structural highlights
FunctionBRKA_BORPE Inhibits the classical pathway of complement activation and prevents accumulation of deposited C4.[1] Publication Abstract from PubMedWhooping cough (pertussis) is a highly contagious acute respiratory illness of humans caused by the Gram-negative bacterial pathogen Bordetella pertussis. The AT (autotransporter) BrkA (Bordetella serum-resistance killing protein A) is an important B. pertussis virulence factor that confers serum resistance and mediates adherence. In the present study, we have solved the crystal structure of the BrkA beta-domain at 3 A (1 A=0.1 nm) resolution. Special features are a hairpin-like structure formed by the external loop L4, which is observed fortuitously sitting inside the pore of the crystallographic adjacent beta-domain, and a previously undiscovered hydrophobic cavity formed by patches on loop L4 and beta-strands S5 and S6. This adopts a ubiquitous structure characteristic of all AT beta-domains. Mutagenesis studies have demonstrated that the hairpin-like structure and hydrophobic cavity are crucial for BrkA passenger domain (virulence effector) translocation. This structure helps in understanding the molecular mechanism of AT assembly and secretion and provides a potential target for anti-pertussis drug design. Autotransporter passenger domain secretion requires a hydrophobic cavity at the extracellular entrance of the beta-domain pore.,Zhai Y, Zhang K, Huo Y, Zhu Y, Zhou Q, Lu J, Black I, Pang X, Roszak AW, Zhang X, Isaacs NW, Sun F Biochem J. 2011 May 1;435(3):577-87. PMID:21306302[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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