TABLE 2.
Nonenzymatic formation of PRAa
| Step no. or description | Status or valueb for indicated reaction no.
|
||||
|---|---|---|---|---|---|
| 1 | 2 | 3 | 4 | 5 | |
| Step 1 | |||||
| Additions | |||||
| Anthranilate | + | + | + | − | + |
| PRPP | + | + | − | + | + |
| ATP | − | − | − | − | + |
| TrpD | − | + | + | + | + |
| Step 2 | |||||
| Measurement of [1-14C] GAR formation | 74 | 374 | 59 | 65 | 290 |
a
Assay conditions were as described in the text, with five initial reaction mixtures containing the indicated additions. Following incubation, protein was removed to generate the eluant of the corresponding number. The eluants were added to the reaction mixture containing NH3, ATP, PurD, and [14C]glycine, and GAR formed was monitored by phosphorimage analyses.
b
Numbers represent phosphorimager units representing amounts of GAR formed.