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

Karakus Y. , GOC G., BALCI S., YORKE B. A. , Trinh C. H. , McPherson M. J. , ...Daha Fazla

ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY, cilt.74, ss.979-985, 2018 (SCI İndekslerine Giren Dergi) identifier identifier identifier

  • Cilt numarası: 74
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1107/s2059798318010628
  • Sayfa Sayıları: ss.979-985


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 angstrom 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.