1xvq
From Proteopedia
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| , resolution 1.75Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , | ||||||
| Gene: | tpx (Mycobacterium tuberculosis) | ||||||
| Domains: | PRX_Atyp2cys | ||||||
| Resources: | FirstGlance, OCA, PDBsum, JenaLib, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of thiol peroxidase from Mycobacterium tuberculosis
Overview
A thiol peroxidase (Tpx) from Mycobacterium tuberculosis was functionally analyzed. The enzyme shows NADPH-linked peroxidase activity using a thioredoxin-thioredoxin reductase system as electron donor, and anti-oxidant activity in a thiol-dependent metal-catalyzed oxidation system. It reduces H2O2, t-butyl hydroperoxide, and cumene hydroperoxide, and is inhibited by sulfhydryl reagents. Mutational studies revealed that the peroxidatic (Cys60) and resolving (Cys93) cysteine residues are critical amino acids for catalytic activity. The X-ray structure determined to a resolution of 1.75 A shows a thioredoxin fold similar to that of other peroxiredoxin family members. Superposition with structural homologues in oxidized and reduced forms indicates that the M. tuberculosis Tpx is a member of the atypical two-Cys peroxiredoxin family. In addition, the short distance that separates the Calpha atoms of Cys60 and Cys93 and the location of these cysteine residues in unstructured regions may indicate that the M. tuberculosis enzyme is oxidized, though the side-chain of Cys60 is poorly visible. It is solely in the reduced Streptococcus pneumoniae Tpx structure that both residues are part of two distinct helical segments. The M. tuberculosis Tpx is dimeric both in solution and in the crystal structure. Amino acid residues from both monomers delineate the active site pocket.
About this Structure
1XVQ is a Single protein structure of sequence from Mycobacterium tuberculosis. Full crystallographic information is available from OCA.
Reference
Functional and structural characterization of a thiol peroxidase from Mycobacterium tuberculosis., Rho BS, Hung LW, Holton JM, Vigil D, Kim SI, Park MS, Terwilliger TC, Pedelacq JD, J Mol Biol. 2006 Sep 1;361(5):850-63. Epub 2006 Jun 27. PMID:16884737
Page seeded by OCA on Wed Mar 26 06:12:58 2008
Categories: Mycobacterium tuberculosis | Single protein | Holton, J M. | Hung, L W. | Kim, S I. | Park, M S. | Pedelacq, J D. | Rho, B S. | TBSGC, TB Structural Genomics Consortium. | Terwilliger, T C. | Vigil, D. | Protein structure initiative | Psi | Structural genomic | Tb structural genomics consortium | Tbsgc | Thioredoxin fold
