Table 3. Substrate specificity of Dao enzymes.
| Protein | RtDao | CgDao1 | CgDao2 | CgDao3 | Concordance with growth phenotypes a |
|---|---|---|---|---|---|
| D-Ala | 41.22 | 0.040 | 0.218* | 0.043 | Yes-dao2Δ |
| D-Asp | 0.97 | 0.916* | 0.053 | 0.049 | Yes b |
| D-Glu | 73.86 | 0.049 | 0.080 | 0.032 | No-dao3Δ |
| D-His | 41.26 | 0.049 | 0.128* | 0.031 | Yes-dao2Δ |
| D-Leu | 15.84 | 0.044 | 0.153* | 0.045 | Yes-dao2Δ |
| D-Met | 27.77 | 0.050 | 0.64* | 0.040 | Yes-dao2Δ |
| D-Phe | 3.97 | 0.046 | 0.043 | 0.031 | No-dao2Δ |
| D-Pro | 39.81 | 0.054 | 0.136* | 0.041 | Yes-dao2Δ |
| D-Ser | 31.13 | 0.062 | 0.129* | 0.044 | Yes-dao2Δ |
| D-Thr | 17.70 | 0.040 | 0.052 | 0.036 | No-dao2Δ |
| D-Val | 50.55 | 0.055 | 1.009* | 0.039 | Yes-dao2Δ |
a Substrate specificity of CgDao enzymes (nM H2O2/ug crude extract) was compared to the growth phenotypes of Cgdao mutants listed in Table 2. “Yes” or “No” designates whether the ability to oxidize D-amino acid is concordant with the growth phenotypes of the specified CgdaoΔ mutant. The experiments were repeated twice and the representative data are shown.
b CgDao1 showed the clearest concordant substrate specificity with Cgdao1Δ growth phenotype.
* Activity is at least two fold higher than the control activity of CgDao using L-amino acid as substrate.