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http://purl.uniprot.org/citations/30897158http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/30897158http://www.w3.org/1999/02/22-rdf-syntax-ns#typehttp://purl.uniprot.org/core/Journal_Citation
http://purl.uniprot.org/citations/30897158http://www.w3.org/2000/01/rdf-schema#comment"The carboxy-terminal domain of the BBK32 protein from Borrelia burgdorferi sensu stricto, termed BBK32-C, binds and inhibits the initiating serine protease of the human classical complement pathway, C1r. In this study we investigated the function of BBK32 orthologues of the Lyme-associated Borrelia burgdorferi sensu lato complex, designated BAD16 from B. afzelii strain PGau and BGD19 from B. garinii strain IP90. Our data show that B. afzelii BAD16-C exhibits BBK32-C-like activities in all assays tested, including high-affinity binding to purified C1r protease and C1 complex, and potent inhibition of the classical complement pathway. Recombinant B. garinii BGD19-C also bound C1 and C1r with high-affinity yet exhibited significantly reduced in vitro complement inhibitory activities relative to BBK32-C or BAD16-C. Interestingly, natively produced BGD19 weakly recognized C1r relative to BBK32 and BAD16 and, unlike these proteins, BGD19 did not confer significant protection from serum killing. Site-directed mutagenesis was performed to convert BBK32-C to resemble BGD19-C at three residue positions that are identical between BBK32 and BAD16 but different in BGD19. The resulting chimeric protein was designated BXK32-C and this BBK32-C variant mimicked the properties observed for BGD19-C. To query the disparate complement inhibitory activities of BBK32 orthologues, the crystal structure of BBK32-C was solved to 1.7Å limiting resolution. BBK32-C adopts an anti-parallel four-helix bundle fold with a fifth alpha-helix protruding from the helical core. The structure revealed that the three residues targeted in the BXK32-C chimera are surface-exposed, further supporting their potential relevance in C1r binding and inhibition. Additional binding assays showed that BBK32-C only recognized C1r fragments containing the serine protease domain. The structure-function studies reported here improve our understanding of how BBK32 recognizes and inhibits C1r and provide new insight into complement evasion mechanisms of Lyme-associated spirochetes of the B. burgdorferi sensu lato complex."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.org/dc/terms/identifier"doi:10.1371/journal.ppat.1007659"xsd:string
http://purl.uniprot.org/citations/30897158http://purl.org/dc/terms/identifier"doi:10.1371/journal.ppat.1007659"xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Xie J."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Xie J."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Skare J.T."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Skare J.T."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Keightley A."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Keightley A."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Zhi H."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Zhi H."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Garcia B.L."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Garcia B.L."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Garrigues R.J."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/author"Garrigues R.J."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/date"2019"xsd:gYear
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/date"2019"xsd:gYear
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/name"PLoS Pathog."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/name"PLoS Pathog"xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/pages"e1007659"xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/pages"e1007659"xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/title"Structural determination of the complement inhibitory domain of Borrelia burgdorferi BBK32 provides insight into classical pathway complement evasion by Lyme disease spirochetes."xsd:string
http://purl.uniprot.org/citations/30897158http://purl.uniprot.org/core/title"Structural determination of the complement inhibitory domain of Borrelia burgdorferi BBK32 provides insight into classical pathway complement evasion by Lyme disease spirochetes."xsd:string
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