8czp
From Proteopedia
2.25 angstrom resolution crystal structure of as-isolated KatG from Mycobacterium tuberculosis with an MYW cofactor
Structural highlights
FunctionKATG_MYCTU Bifunctional enzyme with both catalase and broad-spectrum peroxidase activity. Displays also NADH oxidase, isoniazid (INH) lyase and isonicotinoyl-NAD synthase activity. May play a role in the intracellular survival of mycobacteria. May be involved in DNA repair. Partly complements recA-deficient E.coli cells exposed to UV radiation, mitomycin C or hydrogen peroxide. Increases resistance to mitomycin C in E.coli cells deficient for either uvrA, uvrB or uvrC.[1] Publication Abstract from PubMedBifunctional catalase-peroxidase (KatG) features a posttranslational methionine-tyrosine-tryptophan (MYW) crosslinked cofactor crucial for its catalase function, enabling pathogens to neutralize hydrogen peroxide during infection. We discovered the presence of indole nitrogen-linked hydroperoxyl adduct (MYW-OOH) in Mycobacterium tuberculosis KatG in the solution state under ambient conditions, suggesting its natural occurrence. By isolating predominantly MYW-OOH-containing KatG protein, we investigated the chemical stability and functional impact of MYW-OOH. We discovered that MYW-OOH inhibits catalase activity, presenting a unique temporary lock. Exposure to peroxide or increased temperature removes the hydroperoxyl adduct from the protein cofactor, converting MYW-OOH to MYW and restoring the detoxifying ability of the enzyme against hydrogen peroxide. Thus, the N-linked hydroperoxyl group is releasable. KatG with MYW-OOH represents a catalase dormant, but primed, state of the enzyme. These findings provide insight into chemical strategies targeting the bifunctional enzyme KatG in pathogens, highlighting the role of N-linked hydroperoxyl modifications in enzymatic function. Indole-N-Linked Hydroperoxyl Adduct of Protein-Derived Cofactor Modulating Catalase-Peroxidase Functions.,Li J, Duan R, Traore ES, Nguyen RC, Davis I, Griffth WP, Goodwin DC, Jarzecki AA, Liu A Angew Chem Int Ed Engl. 2024 Sep 19:e202407018. doi: 10.1002/anie.202407018. PMID:39300819[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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