FIG. 8.

Time course of CbbRR2 phosphorylation. To better resolve the phosphorylation products, the phosphotransfer reaction was performed under the following conditions: 1.2 μM D696NCbbSR^R96 was preincubated with 25 nM [γ-³²P]ATP for 20 min (time zero), prior to the addition of 24 μM CbbRR2 (A) and its site-directed mutants, D54NCbbRR2 (B) and D195NCbbRR2 (C). Ten-microliter aliquots were removed at the time points indicated. The reaction products were resolved by 12% SDS-PAGE. The phosphorylated proteins are indicated by arrows. (D) Levels of D696NCbbSR^R96 over the time course of phosphotransfer for D696NCbbSR^R96+CbbRR2 (solid line), D696NCbbSR^R96+D54NCbbRR2 (dashed line), and D696NCbbSR^R96+D195NCbbRR2 (dotted line). (E) Levels of phosphorylation for wild-type CbbRR2 (⧫), D54NCbbRR2 (⋄), and D195NCbb RR2 (×).