28LK
Crystal structure of complement-inhibiting protein ChiB of Borrelia recurrentis
Summary for 28LK
| Entry DOI | 10.2210/pdb28lk/pdb |
| Descriptor | complement-inhibiting protein ChiB, 2-(HEXADECANOYLOXY)-1-[(PHOSPHONOOXY)METHYL]ETHYL HEXADECANOATE, GLYCEROL, ... (4 entities in total) |
| Functional Keywords | borrelia recurrentis, louse-borne relapsing fever, surface protein, complement targeting and host interacting protein, complement-inhibiting protein, protein binding |
| Biological source | Borrelia recurrentis |
| Total number of polymer chains | 1 |
| Total formula weight | 32553.98 |
| Authors | Fritz-Wolf, K.,Rahlfs, S.,Przyborski, J.M.,Stumpf, M.,Roettgerding, F.,Kraiczy, P. (deposition date: 2026-02-05, release date: 2026-05-06) |
| Primary citation | Rottgerding, F.,Reyer, F.,Gerlach, E.,Amborn, M.,Duschek, N.,Schultze, T.G.,Fingerle, V.,Roome, C.M.,Stumpf, M.,Becker, K.,Rahlfs, S.,Przyborski, J.M.,Kraiczy, P.,Fritz-Wolf, K. Complement inhibition by a unique cluster of immunomodulatory outer surface proteins of Borrelia recurrentis. Nat Commun, 17:-, 2026 Cited by PubMed Abstract: Borrelia recurrentis, the agent of louse-borne relapsing fever, causes a poverty-associated, infectious disease of high mortality. Here, we identified and characterized five Complement targeting and Host Interacting proteins, ChiA to ChiE displaying immunomodulatory functions. Almost all Chi homologs inhibit complement activation by direct binding of key components, block membrane attack complex formation, and interact with plasminogen. Borrelia proteins protect susceptible spirochetes from complement-mediated killing and ChiB, ChiC, and ChiD facilitate serum resistance. X-ray structures of ChiA and ChiB, along with AlphaFold models of ChiC, ChiD, and ChiE, reveal a conserved, compact eight-helix fold with a central hydrophobic pocket and a unique S-domain-feature distinct from all known Borrelia proteins. Notably, ChiC and ChiE harbor conserved cysteines forming a reversible disulfide bridge, indicating redox-responsive function. Our findings identify a protein family of functionally related immune evasion factors, advancing our understanding of the underlying mechanisms of complement resistance in this neglected, human pathogenic microorganism. PubMed: 42050325DOI: 10.1038/s41467-026-72359-y PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (1.5 Å) |
Structure validation
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