Figure 2 - Overall folds and active sites of human 2OG oxygenases.

(a) FIH, the human asparaginyl hydroxylase involved in the oxygen sensing mechanism, with HIF-1 Asn803 (ref. 8; Protein Data Bank (PDB) code 1H2K). (b) Human JMJD2A, which is involved in demethylation of methyllysyl histone residues²⁶ (Ni(II) substituting for Fe(II); PDB code 2OQ6). (c) AsnO, the asparagine hydroxylase from Streptomyces coelicolor A3(2) involved in secondary metabolism²⁹ (PDB code 2OG7). Color codes: dark blue, DSBH fold; light blue, helix; white, loop; green, substrate/product; gold, Fe(II)-binding residues. NOG, N-oxalylglycine (2OG analog).