In the Regulation of Glutamine Synthetase Activity, an Important Regulatory $\alpha$

Multiple Choice

In the regulation of glutamine synthetase activity, an important regulatory protein, P_II exists in two states, one with UMP covalently bound (P_II-UMP) , the other without (P_II) . Which of the following statements regarding $\alpha$ -ketoglutarate and P_II is correct?

A) $\alpha$ -ketoglutarate binds to P_II causing inhibition of adenylyltransferase
B) $\alpha$ -ketoglutarate binds to P_II causing activation of adenylyltransferase
C) $\alpha$ -ketoglutarate binds to P_II-UMP causing inhibition of adenylyltransferase
D) $\alpha$ -ketoglutarate binds to P_II-UMP causing activation of adenylyltransferase
E) $\alpha$ -ketoglutarate does not bind to either form of P_II