TABLE 2.
Kinetic parameters for wild-type and mutant BbXFPK
| Enzyme | Kcat | Apparent Km |
Cofactor in mutant structuresa | |
|---|---|---|---|---|
| F6P | Pi | |||
| min−1 | mm | |||
| WTb | 1,540 ± 60 | 9.7 ± 0.3 | 1.2 ± 0.2 | |
| H64A | NAc | NA | NA | Tricyclic ring form of ThDP |
| H64N | NA | NA | NA | |
| H97A | NA | NA | NA | (CDNGd) |
| H97N | NA | NA | NA | (CDNGd) |
| H142A | 12.2 ± 0.9 | 7.4 ± 0.6 | 1.7 ± 0.2 | AcThDP |
| H142N | 39.2 ± 1.2 | 7.2 ± 0.8 | 2.6 ± 0.5 | |
| H320A | NA | NA | NA | AcThDP |
| H320N | NA | NA | NA | |
| Q321A | 59.5 ± 2.5 | 4.4 ± 0.3 | 1.6 ± 0.2 | |
| S440A | 350 ± 11 | 53.5 ± 1.8 | 0.57 ± 0.04 | |
| E479A | NA | NA | NA | |
| Y501F | 197 ± 4 | 1.4 ± 0.2 | 25.5 ± 1.7 | |
| H548A | 100 ± 3 | 2.3 ± 0.7 | 0.52 ± 0.16 | |
| N549A | NA | NA | NA | |
| H553A | NA | NA | NA | ThDP |
| H553N | NA | NA | NA | |
| K605A | NA | NA | NA | |
a Crystallographic data collected after soaking in 27 mm F6P for 5 min. See supplemental Table 3 for details.
b The data are taken from (24).
c NA, no activity was detected.
d CDNG, crystals did not grow.