Download MendeleyStructure of Phenoxazinone Synthase from Streptomyces Antibioticus Reveals a New Type 2 Copper Center.
Smith, A.W., Camara-Artigas, A., Wang, M., Allen, J.P., Francisco, W.A.(2006) Biochemistry 45: 4378
- PubMed: 16584173
- DOI: https://doi.org/10.1021/bi0525526
- Primary Citation of Related Structures:
3GYR - PubMed Abstract:
The multicopper oxidase phenoxazinone synthase (PHS) catalyzes the penultimate step in the biosynthesis of the antibiotic actinomycin D by Streptomyces antibioticus. PHS exists in two oligomeric forms: a dimeric form and a hexameric form, with older actinomycin-producing cultures containing predominately the hexameric form. The structure of hexameric PHS has been determined using X-ray diffraction to a resolution limit of 2.30 A and is found to contain several unexpected and distinctive features. The structure forms a hexameric ring that is centered on a pseudo 6-fold axis and has an outer diameter of 185 A with a large central cavity that has a diameter of 50 A. This hexameric structure is stabilized by a long loop connecting two domains; bound to this long loop is a fifth copper atom that is present as a type 2 copper. This copper atom is not present in any other multicopper oxidase, and its presence appears to stabilize the hexameric structure.
Organizational Affiliation:
Department of Chemistry and Biochemistry, Arizona State University, Tempe Arizona 85287-1604, USA.
