2HJI
Structural model for the Fe-containing isoform of acireductone dioxygenase
Summary for 2HJI
| Entry DOI | 10.2210/pdb2hji/pdb |
| Related | 1VR3 1ZRR |
| NMR Information | BMRB: 7103 |
| Descriptor | E-2/E-2' protein, FE (II) ION (3 entities in total) |
| Functional Keywords | dioxygenase, non-heme iron, isozyme, methionine salvage, structural entropy, oxidoreductase |
| Biological source | Klebsiella oxytoca |
| Total number of polymer chains | 1 |
| Total formula weight | 20275.26 |
| Authors | Pochapsky, T.C.,Ju, T.,Maroney, M.J.,Chai, S.C. (deposition date: 2006-06-30, release date: 2006-10-24, Last modification date: 2024-05-29) |
| Primary citation | Ju, T.,Goldsmith, R.B.,Chai, S.C.,Maroney, M.J.,Pochapsky, S.S.,Pochapsky, T.C. One Protein, Two Enzymes Revisited: A Structural Entropy Switch Interconverts the Two Isoforms of Acireductone Dioxygenase J.Mol.Biol., 363:823-834, 2006 Cited by PubMed Abstract: Acireductone dioxygenase (ARD) catalyzes different reactions between O2 and 1,2-dihydroxy-3-oxo-5-(methylthio)pent-1-ene (acireductone) depending upon the metal bound in the active site. Ni2+ -ARD cleaves acireductone to formate, CO and methylthiopropionate. If Fe2+ is bound (ARD'), the same substrates yield methylthioketobutyrate and formate. The two forms differ in structure, and are chromatographically separable. Paramagnetism of Fe2+ renders the active site of ARD' inaccessible to standard NMR methods. The structure of ARD' has been determined using Fe2+ binding parameters determined by X-ray absorption spectroscopy and NMR restraints from H98S ARD, a metal-free diamagnetic protein that is isostructural with ARD'. ARD' retains the beta-sandwich fold of ARD, but a structural entropy switch increases order at one end of a two-helix system that bisects the beta-sandwich and decreases order at the other upon interconversion of ARD and ARD', causing loss of the C-terminal helix in ARD' and rearrangements of residues involved in substrate orientation in the active site. PubMed: 16989860DOI: 10.1016/j.jmb.2006.08.060 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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