A5051035762- Escherichia coli research studies
- Salmonella and Campylobacter epidemiology
- Bacterial Genetics and Biotechnology
- Microbial metabolism and enzyme function
- Hemoglobin structure and function
- Biochemical Acid Research Studies
- Cancer Research and Treatments
- Bacteriophages and microbial interactions
- Yersinia bacterium, plague, ectoparasites research
- Clostridium difficile and Clostridium perfringens research
- Lipid Membrane Structure and Behavior
- Viral gastroenteritis research and epidemiology
- Vibrio bacteria research studies
- Phytochemicals and Antioxidant Activities
- Porphyrin Metabolism and Disorders
- Free Radicals and Antioxidants
- Antibiotic Resistance in Bacteria
- Toxin Mechanisms and Immunotoxins
- Enzyme Structure and Function
- Underwater Vehicles and Communication Systems
- Spacecraft and Cryogenic Technologies
- Tea Polyphenols and Effects
- Antioxidant Activity and Oxidative Stress
- Protist diversity and phylogeny
- Galectins and Cancer Biology
Centre for Structural Systems Biology
2017-2023
Helmholtz Centre for Infection Research
2017-2023
Max Planck Institute for Infection Biology
2009-2020
University of Trento
2002-2011
Charité - Universitätsmedizin Berlin
2009-2011
Fondazione Umberto Di Mario
2010
Istituto Nazionale Biostrutture e Biosistemi
2007
University of Padua
2004-2005
The long external filament of bacterial flagella is composed several thousand copies a single protein, flagellin. Here, we explore the role played by lysine methylation flagellin in Salmonella, which requires methylase FliB. We show that both flagellins Salmonella enterica serovar Typhimurium, FliC and FljB, are methylated at surface-exposed residues A Typhimurium mutant deficient outcompeted for gut colonization gastroenteritis mouse model, promotes invasion epithelial cells vitro. Lysine...
The delivery of virulence factors into host cells through type III secretion systems is essential for enterobacterial pathogenesis. Molecular chaperones bind specifically to in the bacterial cytosol before secretion. Invasion plasmid gene C (IpgC) a chaperone that binds 2 Shigella : invasion antigens (Ipa) B and C. Here, we report crystal structure IpgC alone complex with binding domain (CBD) IpaB. captures CBD an extended conformation stabilized by conserved residues lining cleft. Analysis...
Many infectious Gram-negative bacteria, including Salmonella typhimurium, require a Type Three Secretion System (T3SS) to translocate virulence factors into host cells. The T3SS consists of membrane protein complex and an extracellular needle together that form continuous channel. Regulated secretion requires the presence SipD at tip in S. typhimurium. Here we report three-dimensional structures individual SipD, fusion with subunit PrgI, SipD:PrgI bile salt, deoxycholate. Assembly involves...
The flagellum is a sophisticated nanomachine and an important virulence factor of many pathogenic bacteria. Flagellar motility enables directed movements towards host cells in chemotactic process, near-surface swimming on cell surfaces crucial for selection permissive entry sites. long external flagellar filament made tens thousands subunits single protein, flagellin, Salmonella serovars alternate expression antigenically distinct flagellin proteins, FliC FljB. However, the role different...
The Type III Secretion Systems (T3SS) needle complex is a conserved syringe-shaped protein translocation nanomachine with mass of about 3.5 MDa essential for the survival and virulence many Gram-negative bacterial pathogens. This system composed membrane-embedded basal body an extracellular that deliver effector proteins into host cells. High-resolution structures T3SS from different organisms infection stages are needed to understand underlying molecular mechanisms translocation. Here, we...
Abstract The type III secretion system (T3SS) is a large, transmembrane protein machinery used by various pathogenic gram‐negative bacteria to transport virulence factors into the host cell during infection. Understanding structure of T3SSs crucial for future developments therapeutics that could target this system. However, much knowledge about T3SS available only Salmonella , and it unclear how large assembly conserved across species. Here, we combined cryo‐electron microscopy,...
Type III secretion systems (TTSSs) utilized by enteropathogenic bacteria require the presence of small, acidic virulence-associated chaperones for effective host cell infection. We adopted a combination biochemical and cellular techniques to define chaperone binding domains (CBDs) in translocators IpaB IpaC associated with IpgC from Shigella flexneri. identified novel CBD furthermore precisely mapped boundaries CBDs both translocator proteins. In single domain associates IpgC. IpaB, we show...
The inhibition by anthocyanins of the free radical-mediated peroxidation linoleic acid in a SDS micelle system was studied at pH 7.4 and 37 degrees C, oxygraphic ESR tecniques. number peroxyl radicals trapped efficiency these molecules trapping reaction, which are two fundamental aspects antioxidant action, were measured discussed light molecular structure. In particular contribution substituents to is -OH>-OCH(3)>-H. By we found that generated acid. life time radical intermediates,...
TPP+ (tetraphenylphosphonium ion) and its analogues were found to act as powerful competitive inhibitors of BSAO (bovine serum amine oxidase). The binding this new class was characterized by kinetic measurements. can bind the active site hydrophobic coulombian interactions. probably occurs in region ‘cation-binding site’[Di Paolo, Scarpa, Corazza, Stevanato Rigo (2002) Biophys. J. 83, 2231–2239]. Under physiological conditions, association constant for is higher than 106 M−1, change enthalpy...
The structures of copper amine oxidases from various sources show good similarity, suggesting similar catalytic mechanisms for all members this enzyme family. However, the optimal substrates each member differ, depending on source and its location. structural factors underlying substrate selectivity still remain to be discovered. With in view, we examined kinetic behaviour pea seedling oxidase with cadaverine hexylamine, first bearing two, second only one, positively charged amino group....
Abstract Translocation of virulence effector proteins through the type III secretion system (T3SS) is essential for many medically relevant Gram‐negative bacteria. The T3SS ATPases are conserved components that specifically recognize chaperone–effector complexes and energize system. It thought functional assemble into a cylindrical structure maintained by their N‐terminal domains. Using size‐exclusion chromatography coupled to multi‐angle light scattering native mass spectrometry, we show in...
Bacterial flagellar filaments are assembled by tens of thousands flagellin subunits, forming 11 helically arranged protofilaments. Each protofilament can take either the two bistable forms L-type or R-type, having slightly different conformations and inter-protofilaments interactions. By mixing ratios R-type protofilaments, flagella adopt multiple filament polymorphs promote bacterial motility. In this study, we investigated hydrogen bonding networks at crystal packing interface in...
Gram-negative pathogens evolved a syringe-like nanomachine, termed type 3 secretion system, to deliver protein effectors into the cytoplasm of host cells. An essential component this system is long helical needle filament that protrudes from bacterial surface and connects cytoplasms bacterium eukaryotic cell. Previous structural research was predominantly focused on reconstituted filaments, which lacked biological context. In work we introduce facile procedure obtain high-resolution cryo-EM...