1uo9: Difference between revisions
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==Overview== | ==Overview== | ||
Deacetoxycephalosporin-C synthase (DAOCS) is a mononuclear ferrous enzyme, that transforms penicillins into cephalosporins by inserting a carbon atom, into the penicillin nucleus. In the first half-reaction, dioxygen and, 2-oxoglutarate produce a reactive iron-oxygen species, succinate and CO2., The oxidizing iron species subsequently reacts with penicillin to give, cephalosporin and water. Here we describe high-resolution structures for, ferrous DAOCS in complex with penicillins, the cephalosporin product, the, cosubstrate and the coproduct. Steady-state kinetic data, quantum-chemical, calculations and the new structures indicate a reaction sequence in which, a 'booby-trapped' oxidizing species is formed. This species is stabilized, by the negative charge of succinate on the iron. The .. | Deacetoxycephalosporin-C synthase (DAOCS) is a mononuclear ferrous enzyme, that transforms penicillins into cephalosporins by inserting a carbon atom, into the penicillin nucleus. In the first half-reaction, dioxygen and, 2-oxoglutarate produce a reactive iron-oxygen species, succinate and CO2., The oxidizing iron species subsequently reacts with penicillin to give, cephalosporin and water. Here we describe high-resolution structures for, ferrous DAOCS in complex with penicillins, the cephalosporin product, the, cosubstrate and the coproduct. Steady-state kinetic data, quantum-chemical, calculations and the new structures indicate a reaction sequence in which, a 'booby-trapped' oxidizing species is formed. This species is stabilized, by the negative charge of succinate on the iron. The binding sites of, succinate and penicillin overlap, and when penicillin replaces succinate, it removes the stabilizing charge, eliciting oxidative attack on itself., Requisite groups of penicillin are within 1 A of the expected position of, a ferryl oxygen in the enzyme-penicillin complex. | ||
==About this Structure== | ==About this Structure== | ||
1UO9 is a | 1UO9 is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Streptomyces_clavuligerus Streptomyces clavuligerus] with FE2 and SIN as [http://en.wikipedia.org/wiki/ligands ligands]. Active as [http://en.wikipedia.org/wiki/Deacetoxycephalosporin-C_synthase Deacetoxycephalosporin-C synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.20.1 1.14.20.1] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1UO9 OCA]. | ||
==Reference== | ==Reference== | ||
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[[Category: vitamin c]] | [[Category: vitamin c]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:33:21 2007'' | ||
