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 regulatory molecules, one of these enzymes clamps down its ten-stranded beta/alpha barrel to bring together the active and specificity sites. ADA deficiency inhibits DNA (15[1])synthesis since (15[1])a buildup of dATP inhibits one of these enzymes that uses two (10[1])ferric iron atoms to generate (-5[1])a stable tyrosyl (tie-roh-SEEL) free (10[1])radical. (15[1])One of (15[1])these (10[1])enzymes uses (*) NADPH to convert gluta·thione from its inactive di·sulfide form to its active (10[1]-5[1])sulf·hydryl (10[1])form. Enzymes of this type convert (-5[1])di·hydro·folate to (10[2]-5[1])tetra·hydro·folate, (-5[1])convert (10[1]-5[1])ribo·nucleotides to (10[2])de·oxy·ribo·nucleotides, and convert (10[1])HMG-CoA to a cholesterol (10[2]-5[1])precursor. For 10 points, what kind of (10[1])enzyme (10[1])adds electrons (-5[1])to its (10[1])substrate? (10[7]0[2])■END■