3E4W

Crystal structure of a 33kDa catalase-related protein from Mycobacterium avium subsp. paratuberculosis. P2(1)2(1)2(1) crystal form.

Summary for 3E4W

• Entry DOI: 10.2210/pdb3e4w/pdb
• Related: 3E4Y
• Descriptor: Putative uncharacterized protein, PROTOPORPHYRIN IX CONTAINING FE, HEXANE-1,6-DIOL, ... (6 entities in total)
• Functional Keywords: heme enzyme, catalase, peroxidase, oxidoreductase
• Biological source: Mycobacterium avium subsp. paratuberculosis
• Total number of polymer chains: 2
• Total formula weight: 71150.27

Authors

Pakhomova, S.,Newcomer, M.E. (deposition date: 2008-08-12, release date: 2009-08-18, Last modification date: 2024-04-03)

Primary citation

Pakhomova, S.,Gao, B.,Boeglin, W.E.,Brash, A.R.,Newcomer, M.E.
The structure and peroxidase activity of a 33-kDa catalase-related protein from Mycobacterium avium ssp. paratuberculosis.
Protein Sci., 18:2559-2568, 2009

PubMed Abstract: True catalases are tyrosine-liganded, usually tetrameric, hemoproteins with subunit sizes of approximately 55-84 kDa. Recently characterized hemoproteins with a catalase-related structure, yet lacking in catalatic activity, include the 40-43 kDa allene oxide synthases of marine invertebrates and cyanobacteria. Herein, we describe the 1.8 A X-ray crystal structure of a 33 kDa subunit hemoprotein from Mycobacterium avium ssp. paratuberculosis (annotated as MAP-2744c), that retains the core elements of the catalase fold and exhibits an organic peroxide-dependent peroxidase activity. MAP-2744c exhibits negligible catalatic activity, weak peroxidatic activity using hydrogen peroxide (20/s) and strong peroxidase activity (approximately 300/s) using organic hydroperoxides as co-substrate. Key amino acid differences significantly impact prosthetic group conformation and placement and confer a distinct activity to this prototypical member of a group of conserved bacterial "minicatalases". Its structural features and the result of the enzyme assays support a role for MAP-2744c and its close homologues in mitigating challenge by a variety of reactive oxygen species.

PubMed: 19827095
DOI: 10.1002/pro.265

Experimental method

X-RAY DIFFRACTION (1.8 Å)