28wu

Crystal Structure of Catalase HPII (KatE) from Escherichia coli

spinqualitylabelsall models 28wu, resolution 2.50Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 28wu is a 4 chain structure with sequence from Escherichia coli BL21(DE3). Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.5Å Ligands: HEM Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CATE_ECOLI Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide. Publication Abstract from PubMed Recombinant protein expression in E. coli is a key methodology for modern biomedical research. Typically, a polyhistidine-tagged ("His-tagged") protein is purified using immobilized metal affinity chromatography (IMAC), achieving close to apparently homogenous target protein preparations. However, contaminant host proteins may nonetheless be co-purified at trace amounts. This includes bacterial catalase, which can even be found crystallized instead of an intended target protein. Here, we found that less than 0.03% of the original endogenous bacterial catalase remaining in a final recombinant protein product can easily be detected in an enzymatic H(2)O(2) (hydrogen peroxide) scavenging assay, because of the high inherent turnover of catalase and its lack of need for additional cofactors. If present in a recombinant protein preparation, this activity may give unintended effects, especially if the target protein is a redox active enzyme, such as glutathione peroxidase, glutaredoxin, ribonucleotide reductase, thioredoxin, or peroxiredoxin. Here, we found that genetic deletion of the two katG and katE genes in a bacterial expression host could fully eliminate catalase from the recombinant protein product without any appreciable loss of final yield. We suggest that this genetic approach is to be preferred for the removal of catalase instead of using more extensive purification schemes. KEY POINTS: * Catalase contaminates recombinant His-tagged proteins purified from E. coli. * A small amount of catalase yields substantial activity due to its high turnover. * Genetic knockout eliminates catalase contamination without compromising yields. A katE katG double-knockout E. coli strain eliminates the risk of catalase contamination in recombinant proteins.,Scholz AT, Coppo L, Nolan E, Hernandez M, Wang X, Mishra P, Schnell R, Pato ZA, Chen Y, Dagnell M, Andor A, Cheng Q, Arner ESJ Appl Microbiol Biotechnol. 2026 Apr 22;110(1):136. doi: , 10.1007/s00253-026-13820-2. PMID:42020871 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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