Crystal structure of a clavaminate synthase–Fe(II)–2‐oxoglutarate–substrate–NO complex: evidence for metal centred rearrangements
Zhang Z., Ren J-S., Harlos K., McKinnon CH., Clifton IJ., Schofield CJ.
Clavaminate synthase (CAS), a 2‐oxoglutarate (2OG) dependent dioxygenase, catalyses three steps in the biosynthesis of clavulanic acid. Crystals of CAS complexed with Fe(II), 2OG and deoxyguanidinoproclavaminate were exposed to nitric oxide (NO) acting as a dioxygen analogue. Prior to exposure with NO, the active site Fe(II) is octahedrally coordinated by a water molecule, the 2‐oxo and 1‐carboxylate groups of 2OG, and the side‐chains of an aspartyl and two histidinyl residues. NO binds to the position previously occupied by the 2OG 1‐carboxylate concomitant with rearrangement of the latter to the position previously occupied by the displaced water.