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Identification of the site of oxidase substrate binding in Scytalidium thermophilum catalase.

Yonca Yuzugullu KarakusGunce GocSinem BalciBriony A YorkeChi H TrinhMichael J McPhersonArwen R Pearson
Published in: Acta crystallographica. Section D, Structural biology (2018)
The catalase from Scytalidium thermophilum is a homotetramer containing a heme d in each active site. Although the enzyme has a classical monofunctional catalase fold, it also possesses oxidase activity towards a number of small organics, including catechol and phenol. In order to further investigate this, the crystal structure of the complex of the catalase with the classical catalase inhibitor 3-amino-1,2,4-triazole (3TR) was determined at 1.95 Å resolution. Surprisingly, no binding to the heme site was observed; instead, 3TR occupies a binding site corresponding to the NADPH-binding pocket in mammalian catalases at the entrance to a lateral channel leading to the heme. Kinetic analysis of site-directed mutants supports the assignment of this pocket as the binding site for oxidase substrates.
Keyphrases
  • minimally invasive
  • binding protein
  • reactive oxygen species
  • transcription factor