9B3H

Structure of a complex between Pasteurella multocida surface lipoprotein, PmSLP-1, and bovine complement factor I

Summary for 9B3H

• Entry DOI: 10.2210/pdb9b3h/pdb
• EMDB information: 44139
• Descriptor: Complement factor I, Pasteurella multocida factor I binding protein, fIbp, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (4 entities in total)
• Functional Keywords: bacterial surface lipoprotein, complement protein, immune evasion, membrane protein
• Biological source: Pasteurella multocida 36950; More
• Total number of polymer chains: 2
• Total formula weight: 103240.66

Authors

Nguyen, Q.H.,Norris, M.J.,Moraes, T.F. (deposition date: 2024-03-19, release date: 2025-04-23, Last modification date: 2025-06-04)

Primary citation

Nguyen, Q.H.,Lai, C.H.R.,Norris, M.J.,Ng, D.,Shah, M.,Lai, C.C.,Isenman, D.E.,Moraes, T.F.
A surface lipoprotein on Pasteurella multocida binds complement factor I to promote immune evasion.
Plos Pathog., 21:e1012686-e1012686, 2025

PubMed Abstract: Pasteurella multocida is the leading cause of wound infections in humans following animals' bites or scratches. This bacterium is also commonly found in the respiratory tract of many mammals and can cause serious diseases resulting in the rapid death of infected animals, especially cattle. To prevent these infections in cattle, a subunit-based vaccine utilizing the surface lipoprotein PmSLP was developed and showed remarkable protection with a single dose administration. Here, we report that PmSLP binds host complement factor I (FI) and facilitates cleavage of complement components C3b and C4b independently of any cofactors (e.g., FH, C4BP), thereby allowing the pathogen to evade host defence. Cryo-EM structure of PmSLP bound to FI reveals that PmSLP stimulates FI enzymatic activity by stabilizing the catalytic domain. This is the first time that a bacterial protein has been shown to directly activate FI independent of complement cofactors and target all arms of the complement cascade.

PubMed: 40327719
DOI: 10.1371/journal.ppat.1012686

Experimental method

ELECTRON MICROSCOPY (4 Å)