3AB0
Crystal structure of complex of the Bacillus anthracis major spore surface protein BclA with ScFv antibody fragment
Summary for 3AB0
| Entry DOI | 10.2210/pdb3ab0/pdb |
| Related | 2Z5W |
| Descriptor | BclA protein, antibody ScFv fragment, heavy chain, antibody ScFv fragment, light chain, ... (4 entities in total) |
| Functional Keywords | exosporium, anthrax, tbcla, scfv complex, immune system |
| Biological source | Bacillus anthracis (anthrax,anthrax bacterium) More |
| Total number of polymer chains | 6 |
| Total formula weight | 75462.72 |
| Authors | Streltsov, V.A. (deposition date: 2009-11-28, release date: 2010-12-01, Last modification date: 2024-10-16) |
| Primary citation | Nuttall, S.D.,Wilkins, M.L.,Streltsov, V.A.,Pontes-Braz, L.,Dolezal, O.,Tran, H.,Liu, C.Q. Isolation, kinetic analysis, and structural characterization of an antibody targeting the Bacillus anthracis major spore surface protein BclA. Proteins, 79:1306-1317, 2011 Cited by PubMed Abstract: One method of laboratory- or field-based testing for anthrax is detection of Bacillus anthracis spores by high-affinity, high specificity binding reagents. From a pool of monoclonal antibodies, we selected one such candidate (A4D11) with high affinity for tBclA, a truncated version of the B. anthracis exosporium protein BclA. Kinetic analysis utilising both standard and kinetic titration on a Biacore biosensor indicated antibody affinities in the 300 pM range for recombinant tBclA, and the A4D11 antibody was also re-formatted into scFv configuration with no loss of affinity. However, assays against B. anthracis and related Bacilli species showed limited binding of intact spores as well as significant cross-reactivity between species. These results were rationalized by determination of the three-dimensional crystallographic structure of the scFv-tBclA complex. A4D11 binds the side of the tBclA trimer, contacting a face of the antigen normally packed against adjacent trimers within the exosporium structure; this inter-spore interface is highly conserved between Bacilli species. Our results indicate the difficulty of generating a high-affinity antibody to differentiate between the highly conserved spore structures of closely related species, but suggest the possibility of future structure-based antibody design for this difficult target. PubMed: 21322055DOI: 10.1002/prot.22971 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.09 Å) |
Structure validation
Download full validation report
