6X0H
Structure of oxidized SidA ornithine hydroxylase with the FAD in the "out" conformation
Summary for 6X0H
| Entry DOI | 10.2210/pdb6x0h/pdb |
| Descriptor | L-ornithine N(5)-monooxygenase, FLAVIN-ADENINE DINUCLEOTIDE, ACETATE ION, ... (6 entities in total) |
| Functional Keywords | flavin-containing monooxygenase, flavoprotein, oxidoreductase |
| Biological source | Aspergillus fumigatus |
| Total number of polymer chains | 4 |
| Total formula weight | 227518.88 |
| Authors | Tanner, J.J.,Campbell, A.C. (deposition date: 2020-05-15, release date: 2020-08-05, Last modification date: 2023-10-18) |
| Primary citation | Campbell, A.C.,Stiers, K.M.,Martin Del Campo, J.S.,Mehra-Chaudhary, R.,Sobrado, P.,Tanner, J.J. Trapping conformational states of a flavin-dependent N -monooxygenase in crystallo reveals protein and flavin dynamics. J.Biol.Chem., 295:13239-13249, 2020 Cited by PubMed Abstract: The siderophore biosynthetic enzyme A (SidA) ornithine hydroxylase from is a fungal disease drug target involved in the production of hydroxamate-containing siderophores, which are used by the pathogen to sequester iron. SidA is an -monooxygenase that catalyzes the NADPH-dependent hydroxylation of l-ornithine through a multistep oxidative mechanism, utilizing a C4a-hydroperoxyflavin intermediate. Here we present four new crystal structures of SidA in various redox and ligation states, including the first structure of oxidized SidA without NADP(H) or l-ornithine bound (resting state). The resting state structure reveals a new active site conformation characterized by large rotations of the FAD isoalloxazine around the C1-'C2' and N10-C1' bonds, coupled to a 10-Å movement of the Tyr-loop. Additional structures show that either flavin reduction or the binding of NADP(H) is sufficient to drive the FAD to the conformation. The structures also reveal protein conformational changes associated with the binding of NADP(H) and l-ornithine. Some of these residues were probed using site-directed mutagenesis. Docking was used to explore the active site of the conformation. These calculations identified two potential ligand-binding sites. Altogether, our results provide new information about conformational dynamics in flavin-dependent monooxygenases. Understanding the different active site conformations that appear during the catalytic cycle may allow fine-tuning of inhibitor discovery efforts. PubMed: 32723870DOI: 10.1074/jbc.RA120.014750 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.087 Å) |
Structure validation
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