Identify all statements that accurately describe the structure of the pyruvate dehydrogenase ( PDH ) complex.
O A regulatory kinase and phosphatase are part of the mammalian PDH complex.
O E2 contains three domains.
O The core of the complex is made up of several copies of E 1 .
O The complex contains multiple copies of each of three enzymes.
O Several copies each of E1 and E3 surround E2 .