1a4e

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Revision as of 08:29, 20 November 2007

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spinqualitylabelsall models 1a4e, resolution 2.4Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

CATALASE A FROM SACCHAROMYCES CEREVISIAE

Overview

The structure of the peroxisomal catalase A from the budding yeast, Saccharomyces cerevisiae, with 515 residues per subunit, has been, determined and refined to 2.4 A resolution. The crystallographic agreement, factors R and Rfree are 15.4% and 19.8%, respectively. A tetramer with, accurate 222-molecular symmetry is located in the asymmetric unit of the, crystal. The conformation of the central core of catalase A, about 300, residues, remains similar to the structure of catalases from distantly, related organisms. In contrast, catalase A lacks a carboxy-terminal domain, equivalent to that found in catalase from Penicillium vitalae, the only, other fungal catalase structure available. Structural peculiarities, related with the heme and NADP(H) binding pockets can be correlated with, biochemical characteristics of the catalase A enzyme. The network of, molecular cavities and channels, filled with solvent molecules, supports, the existence of one major substrate entry and at least two possible, alternative pathways to the heme active site. The structure of the variant, protein Val111Ala, also determined by X-ray crystallography at 2.8 A, resolution, shows a few, well-localized, differences with respect to the, wild-type enzyme. These differences, that include the widening of the, entry channel in its narrowest point, provide an explanation for both the, increased peroxidatic activity and the reduced catalatic activity of this, mutant.

About this Structure

1A4E is a Single protein structure of sequence from Saccharomyces cerevisiae with AZI, SO4 and HEM as ligands. Active as Catalase, with EC number 1.11.1.6 Full crystallographic information is available from OCA.

Reference

Structure of catalase-A from Saccharomyces cerevisiae., Mate MJ, Zamocky M, Nykyri LM, Herzog C, Alzari PM, Betzel C, Koller F, Fita I, J Mol Biol. 1999 Feb 12;286(1):135-49. PMID:9931255

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