8S6C

Crystal structure of Cyanobacterium TDX16 peroxidase

Summary for 8S6C

• Entry DOI: 10.2210/pdb8s6c/pdb
• Descriptor: Lactoperoxidase, PROTOPORPHYRIN IX CONTAINING FE, GLYCEROL, ... (6 entities in total)
• Functional Keywords: heme, oxidoreductase
• Biological source: cyanobacterium TDX16
• Total number of polymer chains: 1
• Total formula weight: 57638.13

Authors

Rozeboom, H.J.,Savino, S.,Fraaije, M.W. (deposition date: 2024-02-27, release date: 2024-12-04, Last modification date: 2025-02-05)

Primary citation

Pecanac, O.,Martin, C.,Savino, S.,Rozeboom, H.J.,Fraaije, M.W.,Loncar, N.
Biochemical and Structural Characterisation of a Bacterial Lactoperoxidase.
Chembiochem, 26:e202400713-e202400713, 2025

PubMed Abstract: Peroxidases belong to a group of enzymes that are widely found in animals, plants and microorganisms. These enzymes are effective biocatalysts for a wide range of oxidations on various substrates. This work presents a biochemical and structural characterization of a novel heme-containing peroxidase from Cyanobacterium sp. TDX16, CyanoPOX. This cyanobacterial enzyme was successfully overexpressed in Escherichia coli as a soluble, heme-containing monomeric enzyme. Although CyanoPOX shares relatively low sequence identity (37 %) with bovine lactoperoxidase, it displays comparable biochemical properties. CyanoPOX is most stable and active in slightly acidic conditions (pH 6-6.5) and moderately thermostable (melting temperature around 48 °C). Several compounds that are typical substrates for mammalian lactoperoxidases were tested to establish the catalytic potential of CyanoPOX. Potassium iodide showed the highest catalytic efficiency (126 mM s), while various aromatic compounds were also readily converted. Structural elucidation of CyanoPOX confirmed the presence of a non-covalently bound b-type heme cofactor that is situated in the central core of the protein. Except for a highly similar overall structure, CyanoPOX also has a conserved active site pocket when compared with mammalian lactoperoxidases. Due to its catalytic properties and high expression in a bacterial host, this newly discovered peroxidase shows promise for applications.

PubMed: 39570012
DOI: 10.1002/cbic.202400713

Experimental method

X-RAY DIFFRACTION (1.74 Å)