2bhf: Difference between revisions

The multi-copper oxidases oxidise substrate molecules by accepting, electrons at a mononuclear copper centre and transferring them to a, trinuclear centre. Dioxygen binds to the trinuclear centre and, following, the transfer of four electrons, is reduced to two molecules of water. The, precise mechanism of this reduction has been unclear, but recent X-ray, structural studies using the CotA endospore coat protein from Bacillus, subtilis have given further insights into the principal stages. It is, proposed that the mechanism involves binding of the dioxygen into the, trinuclear centre so that it is sited approximately symmetrically between, the two type 3 copper ions with one oxygen atom close to the type 2 copper, ion. Further stages involve the formation of a peroxide intermediate and, following the splitting of this intermediate, the migration of the, hydroxide moieties towards the solvent exit channel. The migration steps, are likely to involve a movement of the type 2 copper ion and its, environment. Details of a putative mechanism are described herein based, both on structures already reported in the literature and on structures of, the CotA protein in the oxidised and reduced states and with the addition, of peroxide and the inhibitor, azide.

2BHF is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacillus_subtilis Bacillus subtilis] with CU1 and GOL as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=2BHF OCA].  

''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov  5 13:54:53 2007''