X-Ray Crystallographic Examination of the Active Site of Arginine Kinase

Multiple Choice

X-ray crystallographic examination of the active site of arginine kinase was possible because

A) it could be crystallized in the different structural forms.
B) nitrate could be substituted for phosphate in the reaction.
C) it was readily purified (unlike most other enzymes) .
D) MgADP was involved in the reaction.
E) All of the above.