Fig. 1.

Structure of human AKRs and catalytic tetrad. α/β₈-barrel protein fold of AKRs (A); loop structures at back of barrel (B); and (C) catalytic tetrad. From AKR1C2.NADP⁺ complex (PDB 2hdj). Helices (blue); β-strands (purple); stick model shows position of NADP⁺ and catalytic tetrad in A, and B. Figure produced in Pymol.