The Archaean nrdJ gene encodes a “Class II” type of one of these enzymes that uses deoxy·adenosyl·cobalamin to activate a cysteine residue. In the presence of one of its four (15[1])regulatory molecules, one (15[1])of these enzymes (-5[1])clamps down its ten-stranded beta/alpha barrel to bring together the active and specificity sites. (15[1])ADA deficiency inhibits DNA synthesis since a buildup of dATP inhibits one of these enzymes that (15[2])uses two (15[1])ferric (10[1])iron atoms (10[2])to (10[1])generate (-5[1])a (10[1])stable (10[1])tyrosyl (tie-roh-SEEL) free (-5[1])radical. (10[1])One of these enzymes uses (*) NADPH (10[1])to (10[1])convert gluta·thione from its inactive di·sulfide form to its active (10[1])sulf·hydryl form. Enzymes of this type (10[1])convert di·hydro·folate to tetra·hydro·folate, convert (10[1]-5[1])ribo·nucleotides to (10[1])de·oxy·ribo·nucleotides, and convert (10[1])HMG-CoA to (-5[1])a cholesterol (10[1]-5[1])precursor. (10[1])For 10 points, (10[1]0[2])what kind of enzyme adds electrons to its substrate? (10[3]0[1])■END■