| Structural highlights
Function
CHDC_LISMO Involved in coproporphyrin-dependent heme b biosynthesis (PubMed:27758026, PubMed:31423350). Catalyzes the decarboxylation of Fe-coproporphyrin III (coproheme) to heme b (protoheme IX), the last step of the pathway (PubMed:27758026, PubMed:29536725, PubMed:31423350). The reaction occurs in a stepwise manner with a three-propionate intermediate (PubMed:27758026, PubMed:31423350).[1] [2] [3]
Publication Abstract from PubMed
Chlorite dismutase-like proteins are structurally closely related to functional chlorite dismutases which are heme b-dependent oxidoreductases capable of reducing chlorite to chloride with simultaneous production of dioxygen. Chlorite dismutase-like proteins are incapable of performing this reaction and their biological role is still under discussion. Recently, members of this large protein family were shown to be involved in heme biosynthesis in Gram-positive bacteria, and thus the protein was renamed HemQ in these organisms. In the present work the structural and heme binding properties of the chlorite dismutase-like protein from the Gram-positive pathogen Listeria monocytogenes (LmCld) were analyzed in order to evaluate its potential role as a regulatory heme sensing protein. The homopentameric crystal structure (2.0A) shows high similarity to chlorite-degrading chlorite dismutases with an important difference in the structure of the putative substrate and heme entrance channel. In solution LmCld is a stable hexamer able to bind the low-spin ligand cyanide. Heme binding is reversible with KD-values determined to be 7.2muM (circular dichroism spectroscopy) and 16.8muM (isothermal titration calorimetry) at pH 7.0. Both acidic and alkaline conditions promote heme release. Presented biochemical and structural data reveal that the chlorite dismutase-like protein from L. monocytogenes could act as a potential regulatory heme sensing and storage protein within heme biosynthesis.
Structure and heme-binding properties of HemQ (chlorite dismutase-like protein) from Listeria monocytogenes.,Hofbauer S, Hagmuller A, Schaffner I, Mlynek G, Krutzler M, Stadlmayr G, Pirker KF, Obinger C, Daims H, Djinovic-Carugo K, Furtmuller PG Arch Biochem Biophys. 2015 Jan 17. pii: S0003-9861(15)00026-0. doi:, 10.1016/j.abb.2015.01.010. PMID:25602700[4]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Hofbauer S, Mlynek G, Milazzo L, Puhringer D, Maresch D, Schaffner I, Furtmuller PG, Smulevich G, Djinovic-Carugo K, Obinger C. Hydrogen peroxide-mediated conversion of coproheme to heme b by HemQ - Lessons from the first crystal structure and kinetic studies. FEBS J. 2016 Oct 18. doi: 10.1111/febs.13930. PMID:27758026 doi:https://dx.doi.org/10.1111/febs.13930
- ↑ Milazzo L, Hofbauer S, Howes BD, Gabler T, Furtmüller PG, Obinger C, Smulevich G. Insights into the Active Site of Coproheme Decarboxylase from Listeria monocytogenes. Biochemistry. 2018 Apr 3;57(13):2044-2057. PMID:29536725 doi:10.1021/acs.biochem.8b00186
- ↑ Milazzo L, Gabler T, Puhringer D, Jandova Z, Maresch D, Michlits H, Pfanzagl V, Djinovic-Carugo K, Oostenbrink C, Furtmuller PG, Obinger C, Smulevich G, Hofbauer S. Redox Cofactor Rotates during Its Stepwise Decarboxylation: Molecular Mechanism of Conversion of Coproheme to Heme b. ACS Catal. 2019 Aug 2;9(8):6766-6782. doi: 10.1021/acscatal.9b00963. Epub 2019, Jun 18. PMID:31423350 doi:https://dx.doi.org/10.1021/acscatal.9b00963
- ↑ Hofbauer S, Hagmuller A, Schaffner I, Mlynek G, Krutzler M, Stadlmayr G, Pirker KF, Obinger C, Daims H, Djinovic-Carugo K, Furtmuller PG. Structure and heme-binding properties of HemQ (chlorite dismutase-like protein) from Listeria monocytogenes. Arch Biochem Biophys. 2015 Jan 17. pii: S0003-9861(15)00026-0. doi:, 10.1016/j.abb.2015.01.010. PMID:25602700 doi:https://dx.doi.org/10.1016/j.abb.2015.01.010
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