Table 2.
S-layer and S-layer-associated protein distribution in B. anthracis wild-type and mutant strains
| Protein and fraction | Amt of protein in the indicated strain (%)a |
||||
|---|---|---|---|---|---|
| Wild type | csaB mutant | patA1 mutant | patA2 mutant | patA1 patA2 mutant | |
| Sap | |||||
| Medium | 45 (±5) | 99 (±1) | 38 (±9) | 37 (±4) | 47 (±2) |
| S-layer | 41 (±4) | 0 (±0) | 44 (±3) | 41 (±5) | 44 (±8) |
| Cell | 13 (±7) | 1 (±1) | 17 (±9) | 22 (±3) | 9 (±10) |
| EA1 | |||||
| Medium | 55 (±12) | 100 (±0) | 85 (±5) | 71 (±7) | 88 (±9) |
| S-layer | 43 (±12) | 0 (±0) | 12 (±4) | 24 (±7) | 7 (±4) |
| Cell | 2 (±1) | 0 (±0) | 3 (±0) | 5 (±2) | 5 (±7) |
| BslA | |||||
| Medium | 55 (±1) | 100 (±0) | 95 (±6) | 83 (±6) | 90 (±7) |
| S-layer | 44 (±1) | 0 (±0) | 3 (±4) | 15 (±8) | 9 (±6) |
| Cell | 1 (±1) | 0 (±0) | 1 (±2) | 2 (±2) | 1 (±1) |
| BslO | |||||
| Medium | 19 (±6) | ND | 22 (±13) | 24 (±16) | 55 (±10) |
| S-layer | 77 (±9) | ND | 72 (±2) | 67 (±26) | 45 (±9) |
| Cell | 4 (±3) | ND | 7 (±6) | 10 (±10) | 1 (±1) |
a
The immunoblot signals of two S-layer proteins (Sap, surface array protein, and EA1 extractable antigen 1) and two S-layer-associated proteins (BslA and BslO, S-layer-associated proteins A and O, respectively) in the medium, S-layer, and cell fraction of B. anthracis cultures were quantified in triplicate (Fig. 2). The mean and associated standard deviation of the percent amount in each fraction is presented here. The percentage of Sap that was retained in the S-layer did not change in strains with mutations in patA1 or patA2. These strains showed defects in the S-layer retention of EA1, BslA, and BslO. ND, not detected.