Crystal structure of Trypanosoma cruzi peroxidaseCrystal structure of Trypanosoma cruzi peroxidase

Structural highlights

7opt is a 2 chain structure with sequence from Trypanosoma cruzi. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:X-ray diffraction, Resolution 2.02Å
Ligands:, , ,
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

Q8I1N3_TRYCR

Publication Abstract from PubMed

The protozoan parasite Trypanosoma cruzi is the causative agent of American trypanosomiasis, otherwise known as Chagas disease. To survive in the host, the T. cruzi parasite needs antioxidant defense systems. One of these is a hybrid heme peroxidase, the T. cruzi ascorbate peroxidase-cytochrome c peroxidase enzyme (TcAPx-CcP). TcAPx-CcP has high sequence identity to members of the class I peroxidase family, notably ascorbate peroxidase (APX) and cytochrome c peroxidase (CcP), as well as a mitochondrial peroxidase from Leishmania major (LmP). The aim of this work was to solve the structure and examine the reactivity of the TcAPx-CcP enzyme. Low temperature electron paramagnetic resonance spectra support the formation of an exchange-coupled [Fe(IV)=O Trp(233)(*+)] compound I radical species, analogous to that used in CcP and LmP. We demonstrate that TcAPx-CcP is similar in overall structure to APX and CcP, but there are differences in the substrate-binding regions. Furthermore, the electron transfer pathway from cytochrome c to the heme in CcP and LmP is preserved in the TcAPx-CcP structure. Integration of steady state kinetic experiments, molecular dynamic simulations, and bioinformatic analyses indicates that TcAPx-CcP preferentially oxidizes cytochrome c but is still competent for oxidization of ascorbate. The results reveal that TcAPx-CcP is a credible cytochrome c peroxidase, which can also bind and use ascorbate in host cells, where concentrations are in the millimolar range. Thus, kinetically and functionally TcAPx-CcP can be considered a hybrid peroxidase.

Crystal structure of Trypanosoma cruzi heme peroxidase and characterization of its substrate specificity and compound I intermediate.,Freeman SL, Skafar V, Kwon H, Fielding AJ, Moody PCE, Martinez A, Issoglio FM, Inchausti L, Smircich P, Zeida A, Piacenza L, Radi R, Raven EL J Biol Chem. 2022 Aug;298(8):102204. doi: 10.1016/j.jbc.2022.102204. Epub 2022 , Jun 27. PMID:35772495[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

See Also

References

  1. Freeman SL, Skafar V, Kwon H, Fielding AJ, Moody PCE, Martinez A, Issoglio FM, Inchausti L, Smircich P, Zeida A, Piacenza L, Radi R, Raven EL. Crystal structure of Trypanosoma cruzi heme peroxidase and characterization of its substrate specificity and compound I intermediate. J Biol Chem. 2022 Aug;298(8):102204. doi: 10.1016/j.jbc.2022.102204. Epub 2022 , Jun 27. PMID:35772495 doi:http://dx.doi.org/10.1016/j.jbc.2022.102204

7opt, resolution 2.02Å

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