A5005825764- Enzyme Structure and Function
- Protein Structure and Dynamics
- Amino Acid Enzymes and Metabolism
- Bacterial Genetics and Biotechnology
- Genomics and Phylogenetic Studies
- Microbial Metabolic Engineering and Bioproduction
- Biochemical and Structural Characterization
- Metabolism and Genetic Disorders
- Biochemical Acid Research Studies
- Enzyme-mediated dye degradation
- Probiotics and Fermented Foods
- Protein Hydrolysis and Bioactive Peptides
- RNA and protein synthesis mechanisms
- Photosynthetic Processes and Mechanisms
- Erythrocyte Function and Pathophysiology
- Meat and Animal Product Quality
- Enzyme Catalysis and Immobilization
- Algal biology and biofuel production
- Microbial Natural Products and Biosynthesis
- Enzyme Production and Characterization
- Chemical Synthesis and Analysis
- Chemical synthesis and alkaloids
- Metal-Catalyzed Oxygenation Mechanisms
- Pancreatic function and diabetes
- Bacteriophages and microbial interactions
Heinrich Heine University Düsseldorf
2013-2025
Helmholtz-Zentrum Berlin für Materialien und Energie
2015
University of Duisburg-Essen
2012
Bacteria frequently adapt to high osmolarity surroundings through the accumulation of compatible solutes. Ectoine is a prominent member these types stress protectants and produced via an evolutionarily conserved biosynthetic pathway beginning with L-2,4-diaminobutyrate (DAB) transaminase (TA) EctB. Here, we studied EctB from thermo-tolerant Gram-positive bacterium Paenibacillus lautus (Pl) show that this tetrameric enzyme highly tolerant salt, pH, temperature. During ectoine biosynthesis,...
Abstract Lantibiotics are potent antimicrobial peptides. Nisin is the most prominent member and contains five crucial lanthionine rings. Some clinically relevant bacteria express membrane-associated resistance proteins that proteolytically inactivate nisin. However, substrate recognition specificity of these unknown. Here, we report first three-dimensional structure a nisin protein from Streptococcus agalactiae ( Sa NSR) at 2.2 Å resolution. It an N-terminal helical bundle protease cap core...
The chromatophores of the cercozoan amoeba Paulinella are photosynthetic organelles that evolved from a cyanobacterial endosymbiont. Many nucleus-encoded chromatophore-targeted proteins carry unusual N-terminal targeting signals termed crTPs. crTPs bipartite. Whereas crTPpart1 likely mediates trafficking through secretory pathway is cleaved off during import, crTPpart2 remains attached to its cargo protein. function unknown. To contribute unravel functional role crTPpart2, here we elucidated...
Abstract The metallo-β-lactamase fold is an ancient protein structure present in numerous enzyme families responsible for diverse biological processes. crystal of the hyperthermostable crenarchaeal Igni18 from Ignicoccus hospitalis was solved at 2.3 Å and could resemble a possible first archetype multifunctional metallo-β-lactamase. Ancestral enzymes evolutionary origin are believed to be promiscuous all-rounders. Consistently, Igni18´s activity can cofactor-dependently directed β-lactamase...
α-Aminoxy peptides are peptidomimetic foldamers with high proteolytic and conformational stability. To gain an improved synthetic access to α-aminoxy oligopeptides we used a straightforward combination of solution- solid-phase-supported methods obtained oligomers that showed remarkable anticancer activity against panel cancer cell lines. We solved the first X-ray crystal structure peptide multiple turns around helical axis. The revealed right-handed 28 -helical conformation precisely two...
Lantibiotics are antimicrobial peptides produced by Gram-positive bacteria. Interestingly, several clinically relevant and human pathogenic strains inherently resistant towards lantibiotics. The expression of the genes responsible for lantibiotic resistance is regulated a specific two-component system consisting histidine kinase response regulator. Here, we focused on regulator involved in resistance, NsrR from Streptococcus agalactiae, determined crystal structures its N-terminal receiver...
Ectoine biosynthetic genes (ectABC) are widely distributed in bacteria. Microorganisms that carry them make copious amounts of ectoine as a cell protectant response to high-osmolarity challenges. synthase (EctC; EC 4.2.1.108) is the key enzyme for production this compatible solute and mediates last step biosynthesis. It catalyzes ring closure cyclic molecule. A codon-optimized version ectC from Sphingopyxis alaskensis (Sa) was used overproduction SaEctC protein carrying Strep-tag II peptide...
The zinc-containing corrinoid:coenzyme M methyltransferase MtaA is part of the methanol–coenzyme M–methyltransferase complex Methanosarcina mazei . whole consists three subunits: MtaA, MtaB and MtaC. MtaB–MtaC catalyses cleavage methanol (bound to MtaB) transfer methyl group onto cobalt cob(I)alamin MtaC). MtaA–MtaC from methyl-cob(III)alamin MtaC) coenzyme MtaA). crystal structure M. barkeri has previously been determined. Here, structures in a substrate-free but Zn 2+ -bound state with...
The ectoine hydroxylase (EctD) is a member of the non-haem-containing iron(II)- and 2-oxoglutarate-dependent dioxygenase superfamily. Its mononuclear iron centre prerequisite for activity this enzyme promotes O2-dependent oxidative decarboxylation 2-oxoglutarate, which coupled to two-electron oxidation substrate yield 5-hydroxyectoine. An expression purification protocol EctD from Sphingopyxis alaskensis was developed protein crystallized using sitting-drop vapour-diffusion method. This...
Nisin is a 34-amino-acid antimicrobial peptide produced by Lactococcus lactis belonging to the class of lantibiotics. displays high bactericidal activity against various Gram-positive bacteria, including some human-pathogenic strains. However, there are nisin-non-producing strains that naturally resistant owing presence nsr gene within their genome. The encoded protein, NSR, cleaves off last six amino acids nisin, thereby reducing its efficacy. An expression and purification protocol has...
Toxoplasma gondii is a widely distributed apicomplexan parasite causing toxoplasmosis, critical health issue for immunocompromised individuals and congenitally infected foetuses. Current treatment options are limited in number associated with severe side effects. Thus, novel anti-toxoplasma agents need to be identified developed. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) considered the rate-limiting enzyme non-mevalonate pathway biosynthesis of isoprenoid precursors isopentenyl...
The adhesin involved in diffuse adherence (AIDA-I) from Escherichia coli belongs to the group of autotransporters, specifically type Va secretion system (T5aSS). All autotransporter systems contain a C-terminal β-domain, which forms barrel-like structure outer membrane with hydrophilic pore allowing passenger translocation across membrane. domain harbours biological activity extracellular space and functions, for example, as an adhesin, enzyme toxin. exact transport mechanism is not clear at...
The rapid emergence of microbial multi-resistance against antibiotics has led to intense search for alternatives. One these alternatives are ribosomally synthesized and post-translationally modified peptides (RiPPs), especially lantibiotics. They active in a low nanomolar range their high stability is due the presence characteristic (methyl-) lanthionine rings, which makes them promising candidates as bacteriocides. However, innate resistance lantibiotics exists nature, emphasizing need...
A number of Gram-positive bacteria produce a class bacteriocins called `lantibiotics'. These lantibiotics are ribosomally synthesized peptides that possess high antimicrobial activity against bacteria, including clinically challenging pathogens, and therefore potential alternatives to antibiotics. All lantibiotic producer strains some nonproducer express protein systems circumvent suicidal effect or become resistant, respectively. Two-component consisting response regulator histidine kinase...
The hyperthermophilic crenarchaeon Ignicoccus hospitalis KIN4/I possesses at least 35 putative genes encoding enzymes that belong to the α/β-hydrolase superfamily. One of those genes, metallo-hydrolase-encoding igni18 , was cloned and heterologously expressed in Pichia pastoris . enzyme produced purified its catalytically active form. recombinant successfully crystallized crystal diffracted a resolution 2.3 Å. belonged space group R 32, with unit-cell parameters = b 67.42, c 253.77 Å, α β...