3E4Y: Crystal Structure Of A 33kda Catalase-Related Protein From Mycobacterium Avium Subsp. Paratuberculosis. I2(1)2(1)2(1) Crystal Form

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.
PDB ID: 3E4YDownload
MMDB ID: 76044
PDB Deposition Date: 2008/8/12
Updated in MMDB: 2009/12
Experimental Method:
x-ray diffraction
Resolution: 2.6  Å
Source Organism:
Similar Structures:
Biological Unit for 3E4Y: monomeric; determined by author and by software (PISA)
Molecular Components in 3E4Y
Label Count Molecule
Protein (1 molecule)
Putative Uncharacterized Protein(Gene symbol: MAP_RS13985)
Molecule annotation
Chemicals (4 molecules)
* Click molecule labels to explore molecular sequence information.

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