Figure 6.

Dephosphorylation of NtrC-P by NtrB fragments lacking the G domain. (A) NtrC (2 μM) was incubated with 200 nM NtrB in buffer B. After 10 min, the reaction product was split and to 60 μl of product, 6 μl of the following samples were added: buffer B containing 1 mg/ml BSA (•), TrxHN (♦), TrxSHN (▴), and TrxHN^H139N (■) to a final concentration of 1 μM. Samples (10 μl) were withdrawn at the indicated times, spotted on glass fiber filters and, analyzed as described (3, 4). (B) Dephosphorylation of purified NtrC-³²P in the presence of buffer B containing 1 mg/ml BSA (•), 1 μM TrxSHN (▴), and 1 μM TrxHN^H139N (■).