Putative Coiled-Coil Structural Elements of the BBA68 Protein of Lyme Disease Spirochetes Are Required for Formation of Its Factor H Binding Site
| Autor: | John V. McDowell, Elizabeth A. Rogers, Matthew E. Harlin, Richard T. Marconi |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Protein family
Protein Conformation Molecular Sequence Data Plasma protein binding Biology Microbiology DNA-binding protein Protein structure Bacterial Proteins Humans Amino Acid Sequence Borrelia burgdorferi Binding site Molecular Biology Sequence Deletion Molecular Biology of Pathogens Coiled coil Binding Sites biology.organism_classification Protein Structure Tertiary Biochemistry Complement Factor H Factor H Mutagenesis Site-Directed Protein Binding |
| Zdroj: | Journal of Bacteriology. 187:1317-1323 |
| ISSN: | 1098-5530 0021-9193 |
| Popis: | Factor H and factor H like-protein 1 (FHL-1) are complement regulatory proteins that serve as cofactors for the factor I-mediated cleavage of C3b. Some Lyme disease and relapsing fever spirochete species bind factor H to their surface to facilitate immune evasion. The Lyme disease spirochetes produce several factor H binding proteins (FHBPs) that form two distinct classes. Class I FHBPs (OspE orthologs and paralogs) bind only factor H, while class II FHBPs (BBA68) bind both factor H and FHL-1. BBA68 belongs to a large paralogous protein family, and of these paralogs, BBA69 is the member most closely related to BBA68. To determine if BBA69 can also bind factor H, recombinant protein was generated and tested for factor H binding. BBA69 did not exhibit factor H binding ability, suggesting that among family 54 paralogs, factor H binding is unique to BBA68. To identify the determinants of BBA68 that are involved in factor H binding, truncation and site-directed mutational analyses were performed. These analyses revealed that the factor H binding site is discontinuous and provide strong evidence that coiled-coil structural elements are involved in the formation of the binding site. |
| Databáze: | OpenAIRE |
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