dc.contributor.author	Moubarak, Samah
dc.contributor.author	Rippers, Yvonne
dc.contributor.author	Elghobashi-Meinhardt, Nadia
dc.contributor.author	Mroginski, Maria Andrea
dc.date.accessioned	2022-11-30T10:55:49Z
dc.date.available	2022-11-30T10:55:49Z
dc.date.issued	2022-10-10
dc.date.updated	2022-11-10T12:55:11Z
dc.description.abstract	The function of the recently isolated sulerythrin (SulE) has been investigated using a combination of structural and electronic analyses based on quantum mechanical calculations. In the SulE structure of Fushinobu et al. (2003), isolated from a strictly aerobic archaeon, Sulfolobus tokadaii, a dioxygen-containing species was tentatively included at the active site during crystallographic refinement although the substrate specificity of SulE remains unclear. Studies have suggested that a structurally related enzyme, rubrerythrin, functions as a hydrogen peroxide reductase. Since SulE is a truncated version of rubrerythrin, the enzymes are hypothesized to function similarly. Hence, using available X-ray crystallography data (1.7 Å), we constructed various models of SulE containing a ZnII–Fe active site, differing in the nature of the substrate specificity (O2, H2O2), the oxidation level and the spin state of the iron ion, and the protonation states of the coordinating glutamate residues. Also, the substrate H2O2 is modeled in two possible configurations, differing in the orientation of the hydrogen atoms. Overall, the optimized geometries with an O2 substrate do not show good agreement with the experimentally resolved geometry. In contrast, excellent agreement between crystal structure arrangement and optimized geometries is achieved considering a H2O2 substrate and FeII in both spin states, when Glu92 is protonated. These results suggest that the dioxo species detected at the [ZnFe] active site of sulerythrin is H2O2, rather than an O2 molecule in agreement with experimental data indicating that only the diferrous oxidation state of the dimetal site in rubrerythrin reacts rapidly with H2O2. Based on our computations, we proposed a possible reaction pathway for substrate binding at the ZnFeII site of SulE with a H2O2 substrate. In this reaction pathway, Fe or another electron donor, such as NAD(P)H, catalyzes the reduction of H2O2 to water at the zinc–iron site.
dc.description.sponsorship	DFG, 390540038, EXC 2008: Unifying Systems in Catalysis "UniSysCat"
dc.description.sponsorship	TU Berlin, Open-Access-Mittel – 2022	en
dc.identifier.eissn	2296-889X
dc.identifier.uri	https://depositonce.tu-berlin.de/handle/11303/17752
dc.identifier.uri	https://doi.org/10.14279/depositonce-16539
dc.language.iso	en
dc.rights.uri	http://creativecommons.org/licenses/by/4.0/
dc.subject.ddc	540 Chemie und zugeordnete Wissenschaften	de
dc.subject.other	density functional theory calculations	en
dc.subject.other	structural biology	en
dc.subject.other	computational modeling	en
dc.subject.other	metalloenzyme active site	en
dc.subject.other	electronic properties	en
dc.subject.other	sulerythrin	en
dc.subject.other	quantum mechanical computations	en
dc.subject.other	molecular mechanical computations	en
dc.title	Structural and electronic properties of the active site of [ZnFe] SulE
dc.type	Article
dc.type.version	publishedVersion
dcterms.bibliographicCitation.articlenumber	945415
dcterms.bibliographicCitation.doi	10.3389/fmolb.2022.945415
dcterms.bibliographicCitation.journaltitle	Frontiers in Molecular Biosciences
dcterms.bibliographicCitation.originalpublishername	Frontiers
dcterms.bibliographicCitation.originalpublisherplace	Lausanne
dcterms.bibliographicCitation.volume	9
tub.accessrights.dnb	free
tub.affiliation	Fak. 2 Mathematik und Naturwissenschaften::Inst. Chemie::FG Modellierung biomolekularer Systeme
tub.publisher.universityorinstitution	Technische Universität Berlin

Structural and electronic properties of the active site of [ZnFe] SulE

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