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

ABSTRACT: 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.

SUBMITTER: Yuzugullu Karakus Y

PROVIDER: S-EPMC6173053 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature

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

Yuzugullu Karakus Yonca Y Goc Gunce G Balci Sinem S Yorke Briony A BA Trinh Chi H CH McPherson Michael J MJ Pearson Arwen R AR

Acta crystallographica. Section D, Structural biology 20181002 Pt 10

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 hem ...[more]

PMID: 30289408

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