Brodhun, Florian

[["dc.bibliographiccitation.firstpage","9052"],["dc.bibliographiccitation.issue","23"],["dc.bibliographiccitation.journal","Journal of the American Chemical Society"],["dc.bibliographiccitation.lastpage","9062"],["dc.bibliographiccitation.volume","133"],["dc.contributor.author","Fielding, Alistair J."],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Koch, Christian"],["dc.contributor.author","Pievo, Roberta"],["dc.contributor.author","Denysenkov, Vasyl"],["dc.contributor.author","Feussner, Ivo"],["dc.contributor.author","Bennati, Marina"],["dc.date.accessioned","2018-11-07T08:55:03Z"],["dc.date.available","2018-11-07T08:55:03Z"],["dc.date.issued","2011"],["dc.description.abstract","PpoA is a fungal dioxygenase that produces hydroxylated fatty acids involved in the regulation of the life cycle and secondary metabolism of Aspergillus nidulans. It was recently proposed that this novel enzyme employs two different heme domains to catalyze two separate reactions: within a heme peroxidase domain, linoleic acid is oxidized to (8R)-hydroperoxyoctadecadienoic acid [(8R)-HPODE]; in the second reaction step (8R)-HPODE is isomerized within a P450 heme thiolate domain to 5,8-dihydroxyoctadecadienoic acid. In the present study, pulsed EPR methods were applied to find spectroscopic evidence for the reaction mechanism, thought to involve paramagnetic intermediates. We observe EPR resonances of two distinct heme centers with g-values typical for Fe (III) S = 5/2 high-spin (HS) and Fe(III) S = 1/2 low-spin (LS) hemes. N-14 ENDOR spectroscopy on the S = 5/2 signal reveals resonances consistent with an axial histidine ligation. Reaction of PpoA with the substrate leads to the formation of an amino acid radical on the early millisecond time scale concomitant to a substantial reduction of the S = 5/2 heme signal. High-frequency EPR (95- and 180-GHz) unambiguously identifies the new radical as a tyrosyl, based on g-values and hyperfine couplings from spectral simulations. The radical displays enhanced T-1-spin-lattice relaxation due to the proximity of the heme centers. Further, EPR distance measurements revealed that the radical is distributed among the monomeric subunits of the tetrameric enzyme at a distance of approximately 5 nm. The identification of three active paramagnetic centers involved in the reaction of PpoA supports the previously proposed reaction mechanism based on radical chemistry."],["dc.description.sponsorship","DFG-IRTG [1422]; Max Planck Society"],["dc.identifier.doi","10.1021/ja202207t"],["dc.identifier.isi","000291667600049"],["dc.identifier.pmid","21548577"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22816"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Chemical Soc"],["dc.relation.issn","0002-7863"],["dc.title","Multifrequency Electron Paramagnetic Resonance Characterization of PpoA, a CYP450 Fusion Protein that Catalyzes Fatty Acid Dioxygenation"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","553"],["dc.bibliographiccitation.journal","Biochemical Journal"],["dc.bibliographiccitation.lastpage","565"],["dc.bibliographiccitation.volume","425"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Schneider, Stefan"],["dc.contributor.author","Goebel, Cornelia"],["dc.contributor.author","Hornung, Ellen"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T08:46:02Z"],["dc.date.available","2018-11-07T08:46:02Z"],["dc.date.issued","2010"],["dc.description.abstract","In Asperyillus nidulans Ppos [psi (precocious sexual inducer)-producing oxygenases] are required for the production of so-called psi factors, compounds that control the balance between the sexual and asexual life cycle of the fungus. The genome of A. nidulans harbours three different ppo genes: ppoA, ppoB and ppoC. For all three enzymes two different haem-containing domains are predicted: a fatty acid haem peroxidase/dioxygenase domain in the N-terminal region and a P450 haem-thiolate domain in the C-terminal region. Whereas PpoA was shown to use both haem domains for its bifunctional catalytic activity (linoleic acid 8-dioxygenation and 8-hydroperoxide isomerization), We found that PpoC apparently only harbours a functional haem peroxidase/dioxygenase domain. Consequently, we observed that PpoC catalyses mainly the dioxygenation of linoleic acid (18:2(Delta 9Z,12Z)), yielding 10-HPODE (10-hydroperoxyoctadecadienoic acid). No isomerase activity was detected. Additionally, 10-HPODE was converted at lower rates into 10-KODE (10-keto-octadecadienoic acid) and 10-HODE (10-hydroxyoctadecadienoic acid). In parallel, decomposition of 10-HPODE into 10-ODA (10-octadecynoic acid) and volatile C-8 alcohols that are, among other things, responsible for the characteristic mushroom flavour. Besides these principle differences we also found that PpoA and PpoC can convert 8-HPODE and 10-HPODE into the respective epoxy alcohols: 12,13-epoxy-8-HOME (where HOME is hydroxyoctadecenoic acid) and 12,13-epoxy-10-HOME. By using site-directed mutagenesis we demonstrated that both enzymes share a similar mechanism for the oxidation of 18:2(Delta 9Z,12Z); they both use a conserved tyrosine residue for catalysis and the directed oxygenation at the C-8 and C-10 is most likely controlled by conserved valine/leucine residues in the dioxygenase domain."],["dc.description.sponsorship","German Research Foundation [1422]"],["dc.identifier.doi","10.1042/BJ20091096"],["dc.identifier.isi","000275099500009"],["dc.identifier.pmid","19878096"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/20594"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Portland Press Ltd"],["dc.relation.issn","0264-6021"],["dc.title","PpoC from Aspergillus nidulans is a fusion protein with only one active haem"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1449"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids"],["dc.bibliographiccitation.lastpage","1457"],["dc.bibliographiccitation.volume","1831"],["dc.contributor.author","Koch, Christian"],["dc.contributor.author","Tria, Giancarlo"],["dc.contributor.author","Fielding, Alistair J."],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Valerius, Oliver"],["dc.contributor.author","Feussner, Kirstin"],["dc.contributor.author","Braus, Gerhard H."],["dc.contributor.author","Svergun, Dmitri I."],["dc.contributor.author","Bennati, Marina"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T09:20:44Z"],["dc.date.available","2018-11-07T09:20:44Z"],["dc.date.issued","2013"],["dc.description.abstract","In plants and mammals, oxylipins may be synthesized via multi step processes that consist of dioxygenation and isomerization of the intermediately formed hydroperoxy fatty acid. These processes are typically catalyzed by two distinct enzyme classes: dioxygenases and cytochrome P450 enzymes. In ascomycetes biosynthesis of oxylipins may proceed by a similar two-step pathway. An important difference, however, is that both enzymatic activities may be combined in a single bifunctional enzyme. These types of enzymes are named Psi-factor producing oxygenases (Ppo). Here, the spatial organization of the two domains of PpoA from Aspergillus nidulans was analyzed by small-angle X-ray scattering and the obtained data show that the enzyme exhibits a relatively flat trimeric shape. Atomic structures of the single domains were obtained by template-based structure prediction and docked into the enzyme envelope of the low resolution structure obtained by SAXS. EPR-based distance measurements between the tyrosyl radicals formed in the activated dioxygenase domain of the enzyme supported the trimeric structure obtained from SAXS and the previous assignment of Tyr374 as radical-site in PpoA. Furthermore, two phenylalanine residues in the cytochrome P450 domain were shown to modulate the specificity of hydroperoxy fatty acid rearrangement. (C) 2013 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.bbalip.2013.06.003"],["dc.identifier.isi","000323588100003"],["dc.identifier.pmid","23797010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28946"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","1388-1981"],["dc.title","A structural model of PpoA derived from SAXS-analysis-Implications for substrate conversion"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1251"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","PLANT PHYSIOLOGY"],["dc.bibliographiccitation.lastpage","1266"],["dc.bibliographiccitation.volume","160"],["dc.contributor.author","Neumann, Piotr"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Sauer, Kristin"],["dc.contributor.author","Herrfurth, Cornelia"],["dc.contributor.author","Hamberg, Mats"],["dc.contributor.author","Brinkmann, Jens"],["dc.contributor.author","Scholz, Julia"],["dc.contributor.author","Dickmanns, Achim"],["dc.contributor.author","Feussner, Ivo"],["dc.contributor.author","Ficner, Ralf"],["dc.date.accessioned","2017-09-07T11:48:22Z"],["dc.date.available","2017-09-07T11:48:22Z"],["dc.date.issued","2012"],["dc.description.abstract","In plants, oxylipins regulate developmental processes and defense responses. The first specific step in the biosynthesis of the cyclopentanone class of oxylipins is catalyzed by allene oxide cyclase (AOC) that forms cis(+)-12-oxo-phytodienoic acid. The moss Physcomitrella patens has two AOCs (PpAOC1 and PpAOC2) with different substrate specificities for C-18- and C-20-derived substrates, respectively. To better understand AOC's catalytic mechanism and to elucidate the structural properties that explain the differences in substrate specificity, we solved and analyzed the crystal structures of 36 monomers of both apo and ligand complexes of PpAOC1 and PpAOC2. From these data, we propose the following intermediates in AOC catalysis: (1) a resting state of the apo enzyme with a closed conformation, (2) a first shallow binding mode, followed by (3) a tight binding of the substrate accompanied by conformational changes in the binding pocket, and (4) initiation of the catalytic cycle by opening of the epoxide ring. As expected, the substrate dihydro analog cis-12,13S-epoxy-9Z,15Z-octadecadienoic acid did not cyclize in the presence of PpAOC1; however, when bound to the enzyme, it underwent isomerization into the corresponding trans-epoxide. By comparing complex structures of the C-18 substrate analog with in silico modeling of the C-20 substrate analog bound to the enzyme allowed us to identify three major molecular determinants responsible for the different substrate specificities (i.e. larger active site diameter, an elongated cavity of PpAOC2, and two nonidentical residues at the entrance of the active site)."],["dc.identifier.doi","10.1104/pp.112.205138"],["dc.identifier.gro","3142446"],["dc.identifier.isi","000310584200009"],["dc.identifier.pmid","22987885"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/8374"],["dc.language.iso","en"],["dc.notes.intern","WoS Import 2017-03-10"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.relation.issn","0032-0889"],["dc.title","Crystal Structures of Physcomitrella patens AOC1 and AOC2: Insights into the Enzyme Mechanism and Differences in Substrate Specificity"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1047"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","FEBS Journal"],["dc.bibliographiccitation.lastpage","1063"],["dc.bibliographiccitation.volume","278"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T08:57:42Z"],["dc.date.available","2018-11-07T08:57:42Z"],["dc.date.issued","2011"],["dc.description.abstract","In nearly every living organism, metabolites derived from lipid peroxidation, the so-called oxylipins, are involved in regulating developmental processes as well as environmental responses. Among these bioactive lipids, the mammalian and plant oxylipins are the best characterized, and much information about their physiological role and biosynthetic pathways has accumulated during recent years. Although the occurrence of oxylipins and enzymes involved in their biosynthesis has been studied for nearly three decades, knowledge about fungal oxylipins is still scarce as compared with the situation in plants and mammals. However, the research performed so far has shown that the structural diversity of oxylipins produced by fungi is high and, furthermore, that the enzymes involved in oxylipin metabolism are diverse and often exhibit unusual catalytic activities. The aim of this review is to present a synopsis of the oxylipins identified so far in fungi and the enzymes involved in their biosynthesis."],["dc.description.sponsorship","German Research Foundation"],["dc.identifier.doi","10.1111/j.1742-4658.2011.08027.x"],["dc.identifier.isi","000288560600007"],["dc.identifier.pmid","21281447"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23456"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1742-464X"],["dc.title","Oxylipins in fungi"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1594"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","FEBS Journal"],["dc.bibliographiccitation.lastpage","1606"],["dc.bibliographiccitation.volume","279"],["dc.contributor.author","Koch, Christian"],["dc.contributor.author","Fielding, Alistair J."],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Bennati, Marina"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T09:10:52Z"],["dc.date.available","2018-11-07T09:10:52Z"],["dc.date.issued","2012"],["dc.description.abstract","Psi factor producing oxygenases (Ppos) are fusion proteins consisting of a peroxidase-like functionality in the N-terminus and a P450-fold in the C-terminal part of the polypeptide chain. It was shown that they are responsible for the production of oxidized fatty acids that play a pivotal role in the control of fungal colonization of plant and mammalian hosts. The similarity of the primary structure of the single domains to various host-derived oxylipin-forming enzymes and functional conservation of these enzymatic activities was the basis for prediction of the 3D conformations of the single domains of a prototype Ppo enzyme. We were able to predict a putative substrate binding pocket in the N-terminal domain of the enzyme and support this finding by site-directed mutagenesis. With the proposed substrate binding mode all known determinants of oxygen insertion are in a reasonable spatial arrangement for catalysis. Additionally, we could identify an arginine and show its involvement in substrate binding by kinetic analysis of the respective variant. While substrate position in the dioxygenase domain is well defined, our results indicate that the substrate binding to the P450 domain is rather unconstrained. Nevertheless an asparagine residue within the I-helix is shown to be involved in catalysis and promotes a shortcut of the typical P450 reaction cycle. Taken together, the results presented here exemplify that fatty acids are oxidized in all kingdoms of life by structural and functional highly conserved enzymes."],["dc.identifier.doi","10.1111/j.1742-4658.2011.08352.x"],["dc.identifier.isi","000302995500008"],["dc.identifier.pmid","21920024"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/26594"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1742-464X"],["dc.title","Linoleic acid positioning in psi factor producing oxygenase A, a fusion protein with an atypical cytochrome P450 activity"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","148"],["dc.bibliographiccitation.issue","3-4"],["dc.bibliographiccitation.journal","Progress in Lipid Research"],["dc.bibliographiccitation.lastpage","170"],["dc.bibliographiccitation.volume","48"],["dc.contributor.author","Andreou, Alexandra"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T08:30:33Z"],["dc.date.available","2018-11-07T08:30:33Z"],["dc.date.issued","2009"],["dc.description.abstract","Lipid peroxidation is common to all biological systems, appearing in developmentally-regulated processes and as a response to environmental changes. Products derived from lipid peroxidation are collectively named oxylipins. Initial lipid peroxidation may either occur by enzymatic or chemical reactions. An array of alternative reactions further converting lipid hydroperoxides gives rise to a large variety of oxylipin classes, some with reported signaling functions in plants, fungi, algae or animals. The structural diversity of oxylipins is further increased by their occurrence either as esters in complex lipids or as free (non-esterified) fatty acid derivatives. The enzymes involved in oxylipin metabolism are diverse and comprise a multitude of examples with interesting and unusual catalytic properties. This review aims at giving an overview on plant, fungal, algal and bacterial oxylipins and the enzymes responsible for their biosynthesis. (C) 2009 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.plipres.2009.02.002"],["dc.identifier.isi","000267472200003"],["dc.identifier.pmid","19268690"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16918"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.relation.issn","0163-7827"],["dc.title","Biosynthesis of oxylipins in non-mammals"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2580"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","ChemBioChem"],["dc.bibliographiccitation.lastpage","2584"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Wechsler, Cindy"],["dc.contributor.author","Meyer, Danilo"],["dc.contributor.author","Loschonsky, Sabrina"],["dc.contributor.author","Funk, Lisa-Marie"],["dc.contributor.author","Neumann, Piotr"],["dc.contributor.author","Ficner, Ralf"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Mueller, Michael"],["dc.contributor.author","Tittmann, Kai"],["dc.date.accessioned","2017-09-07T11:54:48Z"],["dc.date.available","2017-09-07T11:54:48Z"],["dc.date.issued","2015"],["dc.description.abstract","Enantioselective bond making and breaking is a hallmark of enzyme action, yet switching the enantioselectivity of the reaction is a difficult undertaking, and typically requires extensive screening of mutant libraries and multiple mutations. Here, we demonstrate that mutational diversification of a single catalytic hot spot in the enzyme pyruvate decarboxylase gives access to both enantiomers of acyloins acetoin and phenylacetylcarbinol, important pharmaceutical precursors, in the case of acetoin even starting from the unselective wild-type protein. Protein crystallography was used to rationalize these findings and to propose a mechanistic model of how enantioselectivity is controlled. In a broader context, our studies highlight the efficiency of mechanism-inspired and structure-guided rational protein design for enhancing and switching enantioselectivity of enzymatic reactions, by systematically exploring the biocatalytic potential of a single hot spot."],["dc.identifier.doi","10.1002/cbic.201500529"],["dc.identifier.gro","3141766"],["dc.identifier.isi","000367720300005"],["dc.identifier.pmid","26488818"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/835"],["dc.notes.intern","WoS Import 2017-03-10 / Funder: DFG [FOR1296]"],["dc.notes.status","final"],["dc.notes.submitter","PUB_WoS_Import"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.eissn","1439-7633"],["dc.relation.issn","1439-4227"],["dc.title","Tuning and Switching Enantioselectivity of Asymmetric Carboligation in an Enzyme through Mutational Analysis of a Single Hot Spot"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","313"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Bioengineered"],["dc.bibliographiccitation.lastpage","321"],["dc.bibliographiccitation.volume","4"],["dc.contributor.author","O'Connell, Kerry Joan"],["dc.contributor.author","Motherway, Mary O'Connell"],["dc.contributor.author","Hennessey, Alan A."],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Ross, R. Paul"],["dc.contributor.author","Feussner, Ivo"],["dc.contributor.author","Stanton, Catherine"],["dc.contributor.author","Fitzgerald, Gerald F."],["dc.contributor.author","van Sinderen, Douwe"],["dc.date.accessioned","2018-11-07T09:20:02Z"],["dc.date.available","2018-11-07T09:20:02Z"],["dc.date.issued","2013"],["dc.description.abstract","Bifidobacteria are common commensals of the mammalian gastrointestinal tract. Previous studies have suggested that a bifidobacterial myosin cross reactive antigen (MCRA) protein plays a role in bacterial stress tolerance, while this protein has also been linked to the biosynthesis of conjugated linoleic acid (CLA) in bifidobacteria. In order to increase our understanding on the role of MCRA in bifidobacteria we created and analyzed an insertion mutant of the MCRA-encoding gene of B. breve NCFB 2258. Our results demonstrate that the MCRA protein of B. breve NCFB 2258 does not appear to play a role in CLA production, yet is an oleate hydratase, which contributes to bifidobacterial solvent stress protection."],["dc.identifier.doi","10.4161/bioe.24159"],["dc.identifier.isi","000336904300012"],["dc.identifier.pmid","23851389"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/28782"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Landes Bioscience"],["dc.relation.issn","2165-5987"],["dc.relation.issn","2165-5979"],["dc.title","Identification and characterization of an oleate hydratase-encoding gene from Bifidobacterium breve"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","11792"],["dc.bibliographiccitation.issue","18"],["dc.bibliographiccitation.journal","Journal of Biological Chemistry"],["dc.bibliographiccitation.lastpage","11805"],["dc.bibliographiccitation.volume","284"],["dc.contributor.author","Brodhun, Florian"],["dc.contributor.author","Goebel, Cornelia"],["dc.contributor.author","Hornung, Ellen"],["dc.contributor.author","Feussner, Ivo"],["dc.date.accessioned","2018-11-07T08:30:21Z"],["dc.date.available","2018-11-07T08:30:21Z"],["dc.date.issued","2009"],["dc.description.abstract","The homothallic ascomycete Aspergillus nidulans serves as model organism for filamentous fungi because of its ability to propagate with both asexual and sexual life cycles, and fatty acid-derived substances regulate the balance between both cycles. These so-called psi (precocious sexual inducer) factors are produced by psi factor-producing oxygenases (Ppo enzymes). Bioinformatic analysis predicted the presence of two different heme domains in Ppo proteins: in the N-terminal region, a fatty acid heme dioxygenase/peroxidase domain is predicted, whereas in the C-terminal region, a P450 heme thiolate domain is predicted. To analyze the reaction catalyzed by Ppo enzymes, PpoA was expressed in Escherichia coli as an active enzyme. The protein was purified by 62-fold and identified as a homotetrameric ferric heme protein that metabolizes mono-as well as polyunsaturated C-16 and C-18 fatty acids at pH similar to 7.25. The presence of thiolate-ligated heme was confirmed on the basis of sequence alignments and the appearance of a characteristic 450 nm CO-binding spectrum. Studies on its reaction mechanism revealed that PpoA uses different heme domains to catalyze two separate reactions. Within the heme peroxidase domain, linoleic acid is oxidized to (8R)-hydroperoxyoctadecadienoic acid by abstracting a H-atom from C-8 of the fatty acid, yielding a carbon-centered radical that reacts with molecular dioxygen. In the second reaction step, 8-hydroperoxyoctadecadienoic acid is isomerized within the P450 heme thiolate domain to 5,8-dihydroxyoctadecadienoic acid. We identify PpoA as a bifunctional P450 fusion protein that uses a previously unknown reaction mechanism for forming psi factors."],["dc.description.sponsorship","German Research Foundation (IRTG 1422). [IRTG 1422]"],["dc.identifier.doi","10.1074/jbc.M809152200"],["dc.identifier.isi","000265494600011"],["dc.identifier.pmid","19286665"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16877"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Amer Soc Biochemistry Molecular Biology Inc"],["dc.relation.issn","1083-351X"],["dc.relation.issn","0021-9258"],["dc.title","Identification of PpoA from Aspergillus nidulans as a Fusion Protein of a Fatty Acid Heme Dioxygenase/Peroxidase and a Cytochrome P450"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]