Article
Biochemistry & Molecular Biology
Thomas Kluenemann, Manfred Nimtz, Lothar Jaensch, Gunhild Layer, Wulf Blankenfeldt
Summary: Certain facultative anaerobes like the opportunistic human pathogen Pseudomonas aeruginosa can respire on nitrate, leading to difficulties in eradicating infections due to biofilm formation. The denitrification process involves reduction of nitrite to nitric oxide by nitrite reductase NirS, with the essential periplasmic protein NirF playing a crucial but unclear role in the pathway. Crystal structures of NirF and its complex with dihydroheme d(1) have been determined, suggesting that NirF may possess an unknown enzymatic activity rather than simply being a binding protein for heme d(1) derivatives.
Article
Biochemistry & Molecular Biology
Anna Barile, Theo Battista, Annarita Fiorillo, Martino Luigi di Salvo, Francesco Malatesta, Angela Tramonti, Andrea Ilari, Roberto Contestabile
Summary: PLP, the active form of vitamin B6, is crucial in metabolism as an enzyme cofactor. In Escherichia coli, PNPO catalyzes PLP formation and is inhibited by the same molecule through allosteric regulation. Crystallographic studies identified the allosteric site of PLP on PNPO, and mutagenesis of the arginine cage can modulate the enzyme's allosteric properties.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Jenny U. Tran, Breann L. Brown
Summary: 5-Aminolevulinic acid synthase (ALAS) is an enzyme that plays a vital role in heme biosynthesis. It is responsible for the first and rate-limiting step of heme biosynthesis in alpha-proteobacteria and several non-plant eukaryotes. Mutations in the C-terminal region of ALAS have been linked to blood disorders in humans. In Saccharomyces cerevisiae ALAS (Hem1), the C-terminal extension interacts with conserved ALAS motifs and regulates the enzyme's activity and efficiency.
Article
Biochemistry & Molecular Biology
Andrea Dali, Thomas Gabler, Federico Sebastiani, Alina Destinger, Paul Georg Furtmueller, Vera Pfanzagl, Maurizio Becucci, Giulietta Smulevich, Stefan Hofbauer
Summary: Coproporphyrin ferrochelatases (CpfCs) are enzymes that catalyze the penultimate step in the coproporphyrin-dependent heme biosynthesis pathway. The discovery of the correct substrate for these ferrochelatases and the characterization of their binding mode provide valuable insights into the iron insertion process. This knowledge is essential for understanding the preconditions and mechanisms of iron insertion in CpfCs.
Article
Biochemistry & Molecular Biology
Jordan L. Pederick, Jessica C. Woolman, John B. Bruning
Summary: Pseudomonas aeruginosa is a major human pathogen in healthcare settings, and the emergence of drug-resistant strains necessitates the development of new antibiotics. In this study, researchers characterized two enzymes involved in cell wall biosynthesis in P. aeruginosa, and found that inhibiting their activity could be a promising approach for designing new antibiotics. The study provides important insights into potential targets for combating drug resistance in P. aeruginosa.
Review
Biochemistry & Molecular Biology
Ian G. Chambers, Mathilda M. Willoughby, Iqbal Hamza, Amit R. Reddi
Summary: Heme, a hydrophobic iron-containing organic ring that can interact with biological membranes, poses both potential cytotoxicity and crucial regulatory challenges for cells to tightly control its concentration and bioavailability; in addition to membrane-bound transporters and soluble carriers, non-proteinaceous biomolecules like lipids and nucleic acids may play a role in regulating heme trafficking, highlighting the complexity of heme homeostasis.
BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH
(2021)
Review
Plant Sciences
Takayuki Shimizu, Tatsuru Masuda
Summary: Chloroplast biogenesis relies on coordinated expression of chloroplast and nuclear genomes. Retrograde signals emitted from plastids control nuclear gene expression, with gun mutants playing a role in this pathway.
Article
Plant Sciences
Vincent Foelsche, Christopher Grossmann, Andreas S. Richter
Summary: Plant tetrapyrrole biosynthesis (TPS) plays a crucial role in the production of chlorophyll and heme molecules in photosynthetic organisms. This study focused on the role of GUN4 in the TPS pathway and analyzed the effects of GUN4 mutants in vitro and in vivo. The results confirmed the importance of specific amino acids in porphyrin-binding and MgCh activation. Furthermore, expression of different GUN4 mutants had divergent effects on TPS and chlorophyll accumulation in Arabidopsis, indicating the complexity of GUN4's role in plant tetrapyrrole biosynthesis.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Jitka Richtova, Lilach Sheiner, Ansgar Gruber, Shun-Min Yang, Ludek Koreny, Boris Striepen, Miroslav Obornik
Summary: Heme biosynthesis is vital for almost all living organisms and the enzymes in this pathway can be located in various cellular compartments due to factors such as evolutionary origin, demand for the product, substrate availability, and pathway regulation. In some organisms, the heme synthesis pathway combines elements from ancient algal symbionts and hosts. Experimental tests using different algorithms and reporter gene expression confirmed the complex targeting patterns of enzymes in different cellular compartments.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Plant Sciences
Jiarui Yuan, Tingting Ma, Shuiling Ji, Boris Hedtke, Bernhard Grimm, Rongcheng Lin
Summary: This study uncovers the roles of MORF2 and MORF9 in regulating tetrapyrrole biosynthesis and embryogenesis in Arabidopsis thaliana. MORF2 and MORF9 interact directly with multiple tetrapyrrole biosynthesis enzymes and regulators, and display holdase chaperone activity, essential for enzyme accumulation and activity.
Article
Chemistry, Physical
Soumia Merazka, Mohammed Kars, Thierry Roisnel, Mohamed Sidoumou
Summary: The crystal structures of three novel germanium tungstates were studied using single-crystal X-ray diffraction and density functional theory (DFT) calculations. These structures have distorted MO6 (M = Ge/W) octahedra, forming infinite zigzag chains. In Ge x W 1-x O 3 (x - 1/4, 1/2 ), a transition from semiconducting to metallike behavior was observed due to germanium's lower valence acting as a p-type semiconductor. Ge x W 1-x O 3 (x - 1/4, 1/2 ) showed strong reflectivity and absorption in the near-infrared region and weak reflectivity and absorption in the visible region. Ge 1-x WO 4 (x - 0.2) exhibited a narrow band gap (0.89 eV) due to Ge-vacancies, leading to increased absorption and reflectivity in the visible region compared to GeWO4. (c) 2023 Elsevier B.V. All rights reserved.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Biochemistry & Molecular Biology
Ze-Yuan Chen, Hong Yuan, Huamin Wang, Li-Juan Sun, Lu Yu, Shu-Qin Gao, Xiangshi Tan, Ying-Wu Lin
Summary: A simple method was developed to regulate the heme active site of heme protein by generating a cavity through the mutation of an amino acid, followed by covalent modifications with exogenous ligands. This approach efficiently modulated the heme coordination state and protein function, suggesting its potential applicability in the design of functional heme proteins.
Article
Plant Sciences
Tingting Fan, Lena Roling, Boris Hedtke, Bernhard Grimm
Summary: During photoperiodic growth, interaction between ferrochelatase 2 (FC2), protochlorophyllide oxidoreductase (POR), and the regulator FLU suppresses 5-aminolevulinic acid (ALA) synthesis for chlorophyll synthesis, preventing accumulation of potentially deleterious tetrapyrrole intermediates. FC2 stabilizes POR by physical interaction, and disruption of the FC2-POR interaction leads to attenuated ALA suppression and accumulation of photoreactive protochlorophyllide.
Article
Crystallography
Monika Kadela-Tomanek, Ewa Bebenek, Arkadiusz Sokal, Maria Ksiazek, Elwira Chrobak
Summary: The molecular structure of 3-diethoxyphosphoryl-28-[1-(1-deoxy-beta-D-glucopyranosyl)-1H-1,2,3-triazol-4-yl]carbonylbetulin was investigated using various experimental and theoretical methods. It was found that the introduction of a triazole substituent affects the arrangement of molecules in the crystal structure and the formation of hydrogen bonds.
Article
Chemistry, Physical
Wenjian Zhang, William Levason, Gillian Reid
Summary: In this study, a novel manganese-phosphine complex was synthesized and characterized through experimental and analytical methods. The complex undergoes a double P-C coupling reaction and defluorination of aryl groups, resulting in the formation of a stable nine-membered triphosphine macrocyclic complex.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Biotechnology & Applied Microbiology
Shixiang Dai, Falk Harnisch, Mohammad Sufian Bin-Hudari, Nina Sophie Keller, Carsten Vogt, Benjamin Korth
Summary: Microbial electrochemical technology (MET) has shown promise in treating wastewater contaminated with high sulfate concentrations. In this study, flow mode bioelectrochemical sulfate reduction was investigated and achieved comparable removal efficiencies to batch experiments, with significantly increased sulfate removal rates and Coulombic efficiencies. The advantage of flow operation is likely due to higher biomass, stable pH, and a better ratio between sulfate-reducing prokaryotes and homoacetogens.
MICROBIAL BIOTECHNOLOGY
(2023)
Article
Chemistry, Multidisciplinary
Mostafa M. Hamed, Ahmed S. Abdelsamie, Katharina Rox, Christian Schuetz, Andreas M. Kany, Teresa Roehrig, Stefan Schmelz, Wulf Blankenfeldt, Alejandro Arce-Rodriguez, Jose Manuel Borrero-de Acuna, Dieter Jahn, Jessica Rademacher, Felix C. Ringshausen, Nina Cramer, Burkhard Tuemmler, Anna K. H. Hirsch, Rolf W. Hartmann, Martin Empting
Summary: Pseudomonas aeruginosa is a dangerous opportunistic pathogen with alarming resistances to antibiotics. Disarming the bacteria by interfering with their quorum sensing system shows promise as an alternative strategy. This study reports the design and optimization of PqRs inverse agonists, which effectively suppress bacterial pathogenicity and show activity against clinical isolates.
Review
Biotechnology & Applied Microbiology
Markus Stoeckl, Thomas Lange, Paniz Izadi, Sera Bolat, Niklas Teetz, Falk Harnisch, Dirk Holtmann
Summary: The transition of today's fossil fuel based chemical industry towards sustainable production requires improvements in current processes and the development of new bio-based synthesis routes. Gas diffusion electrodes (GDE) show promise for the electrochemical conversion of gaseous reactants such as CO2, and this article highlights their architecture, function, and application in CO2 conversion for subsequent biosynthesis. The review also discusses the use of GDE in microbial fuel cells and the generation of H2O2 for enzymatic reactions, as well as engineering aspects like scale-up and modeling of GDE-based processes.
BIOTECHNOLOGY AND BIOENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Jan Wichmann, Janine Mayer, Mattes Hintmann, Peer Lukat, Wulf Blankenfeldt, Rebekka Biedendieck
Summary: In this study, we successfully enhanced the crystallizability of a penicillin G acylase (PGA) from Bacillus sp. FJAT-27231 (FJAT-PGA) using protein engineering techniques. The improvements were achieved through surface entropy reduction and strengthening of hydrophobic interactions at crystal contacts, leading to accelerated crystallization, lower required PGA and precipitant concentrations, increased crystal yield, and improved impurity tolerance. A total of twelve amino acid exchanges and one deletion resulted in the best crystallizability achieved in this study.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Electrochemistry
Paniz Izadi, Aykut Kas, Philip Haus, Falk Harnisch
Summary: In a circular economy, carbon dioxide can be utilized by electrochemical CO2 reduction reaction (eCO2RR) to produce feed for microbial syntheses. However, the stability of eCO2RR at biocompatible conditions is currently limited to short-term operation. This study evaluates the parameters affecting the stability of eCO2RR performance over a long-term operation and discusses how to overcome these obstacles.
ELECTROCHIMICA ACTA
(2023)
Article
Engineering, Environmental
Benjamin Korth, Joao Pereira, Tom Sleutels, Falk Harnisch, Annemiek Ter Heijne
Summary: This study investigates the energy conversion and biomass yields of electroactive microorganisms (EAM). The results support the hypothesis of restricted energy harvest of EAM and call for an adjusted growth model to improve the understanding and modeling of their energy metabolism. The reported biomass yields are important parameters for designing strategies to influence the interactions between EAM and other microorganisms and assessing the feasibility of microbial electrochemical technologies.
Article
Electrochemistry
Aykut Kas, Paniz Izadi, Falk Harnisch
Summary: This study demonstrates the potential of using tin as an electrocatalyst in halophilic media for achieving maximum formate production rates in microbial synthesis. The findings lay the foundation for further research in this field.
Article
Chemistry, Multidisciplinary
Tatiana E. Gorelik, Peer Lukat, Christian Kleeberg, Wulf Blankenfeldt, Rolf Mueller
Summary: This study evaluated the performance of molecular replacement (MR) procedures for structure analysis of small-molecule crystal structures from 3D electron diffraction (ED) data. By using different data types and search models, MR was successfully conducted at a resolution of 2 angstrom for the crystal structure of Bi-3812.
ACTA CRYSTALLOGRAPHICA A-FOUNDATION AND ADVANCES
(2023)
Article
Chemistry, Multidisciplinary
Micjel Chavez Morejon, Nils Kurig, Yannick S. Tschauder, Falk Harnisch, Regina Palkovits
Summary: This study elucidates key parameters allowing the electrochemical valorization of cellobiose, by creating value-added products by both, anodic oxidation, and cathodic reduction. The first electrochemical reduction of cellobiose to cellobitol was achieved in a divided cell using Pb as cathode, with a conversion rate of up to 49% but with long reaction times (over 26 h) and low coulombic efficiency (4%). The successful synthesis of cellobionic acid was demonstrated by mediated oxidation in an undivided electrochemical cell, with cellobiose oxidation highly selective, achieving up to 92% conversion at 48% coulombic efficiency when using a charge of 2 FE.
Article
Multidisciplinary Sciences
Fangfang Chen, Israfil Yalcin, Mingming Zhao, Chutao Chen, Wulf Blankenfeldt, Frank Pessler, Konrad Buessow
Summary: cis-Aconitate decarboxylase (ACOD1, IRG1) converts cis-aconitate to itaconate, an immunomodulatory and antibacterial metabolite. Mouse ACOD1 is about five times more active than human ACOD1, despite both enzymes having identical active site residues. By introducing isoleucine at position 154 in human ACOD1, which is naturally methionine, the activity of human ACOD1 increased. The change in ACOD1 sequence at position 154 during human evolution leads to a significant decrease in activity, possibly providing a selective advantage in diseases like cancer.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Multidisciplinary
Micjel Chavez Morejon, Alexander Franz, Rohan Karande, Falk Harnisch
Summary: We demonstrate a method for synthesizing adipic acid (AA), a key component of polyamides like Nylon-6,6, from lignin-derived feedstock using a combination of electrochemical hydrogenation and biotransformation. The electrochemical hydrogenation process achieves a 68% yield of cyclohexanol from phenol at a 69% coulombic efficiency, and the electrochemical hydrogenation of an aromatic mixture obtained from lignin depolymerization yields up to 83%. By further biotransformation with recombinant Pseudomonas taiwanensis VLB120, AA is produced at a rate of 0.02 g L-1 h(-1) with a yield of up to 61% in 5 hours.
Article
Chemistry, Multidisciplinary
Santiago T. T. Boto, Bettina Bardl, Falk Harnisch, Miriam A. A. Rosenbaum
Summary: Microbial electrosynthesis (MES) has great potential for recycling carbon dioxide into organic compounds, but the lack of process control and understanding of microbial extracellular electron transfer (EET) hinders further development. This study found that cathodic hydrogen is the dominant electron source for C. ljungdahlii in electroautotrophic MES, leading to superior growth and biosynthesis compared to previous studies. It was also discovered that MES using C. ljungdahlii can produce other products besides acetate, such as glycine and ethanolamine. Understanding the electrophysiology of C. ljungdahlii is key to improving bioprocess strategies in MES research.
Review
Microbiology
Washington Logrono, Sabine Kleinsteuber, Joerg Kretzschmar, Falk Harnisch, Jo De Vrieze, Marcell Nikolausz
FEMS MICROBIOLOGY REVIEWS
(2023)
Article
Engineering, Environmental
Yuting Guo, Luis F. M. Rosa, Yongping Shan, Falk Harnisch, Susann Mueller
Summary: The composition and functions of an anodic microbiome are crucial for both wastewater treatment and current production. The type of substrate and cultivation mode can affect the microorganisms' contribution to these functions. In a laminar flow bioelectrochemical system, the complexity of carbon sources influences the distribution of biomass and the efficiency of current production and carbon removal. Reactors fed with undefined wastewater showed similarities with those fed with acetate, while reactors fed with defined wastewater showed significant differences. The division of labor between current production and substrate degradation is independent of the provided substrates, but the efficiency and types of subcommunities involved depend on the substrates.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Energy & Fuels
Luis F. M. Rosa, Katharina Roehring, Falk Harnisch
Summary: In aviation, carbon-based liquid fuels with high mass and volume specific energy density are needed. This study demonstrates the scale-up production of aviation drop-in fuel-like mixtures from biomass through electrolysing medium chain carboxylic acids, achieving unprecedented electrolysis performance.
Article
Biochemistry & Molecular Biology
Ankita Chadda, Alexander G. Kozlov, Binh Nguyen, Timothy M. Lohman, Eric A. Galburt
Summary: In this study, it was found that the DNA damage response in Mycobacterium tuberculosis differs from well-studied model bacteria. The DNA repair helicase UvrD1 in Mtb is activated through a redox-dependent process and is closely associated with the homo-dimeric Ku protein. Additionally, Ku protein is shown to stimulate the helicase activity of UvrD1.
JOURNAL OF MOLECULAR BIOLOGY
(2024)