Highlights

Atmospheric nitrogen (N2) is, for the most part, an inert gas for living beings on Earth. That is, we cannot directly utilize this vital compound. Therefore, the biochemical nitrogen cycle, and especially the role played by bacteria and plants, is essential to sustaining life on our planet. In some microorganisms, a process known as biological nitrogen fixation occurs, in which nitrogenases, oxygen-sensitive proteins, transform atmospheric nitrogen into forms usable for life. To function, (…)

Researchers from the Institut de Biologie Structurale, the Max Planck Institute for Marine Microbiology, and the Max Planck Institute of Molecular Cell Biology and Genetics have unraveled a key step in the conversion of the toxic carbon monoxide into ethanol performed by the bacterium Clostridium autoethanogenum. The study, published in Nature Chemical Biology, reveals the key role of a tungsten-containing enzyme in this remarkable process, bringing new insight into the sustainable (…)

Baculoviruses are viruses that specifically infect insect cells and play a key role in regulating their populations. They are used both as biological control agents in agronomy and, most importantly, as expression systems for the production of recombinant proteins in structural biology (insect cell culture). Morphologically, Baculoviruses possess a nucleocapsid, the protein assembly that protects and packages the viral DNA, surrounded by a lipid envelope into which viral glycoproteins are (…)

In eukaryotes, U-rich small nuclear RNAs (snRNAs) are integral components of spliceosomes, the cellular machines that mediate the splicing of nascent mRNA. Before their incorporation into spliceosomal particles, snRNAs must be transiently exported to the cytoplasm, where part of their maturation takes place. Although the complex mediating snRNA nuclear export was first identified 25 years ago, the molecular details of its function and assembly have remained unclear. Scientists from the IBS (…)

While humans burn methane to generate energy to warm their homes, some gifted microbes “burn” methane without oxygen to acquire cellular energy. This process is carried out by a specific group of microbes called ANaerobic MEthanotrophic archaea (ANMEs for short), which munch on methane to spit out CO2. Why would these invisible life forms matter? Because they are prime actors in the planetary carbon cycle. In marine sediments without oxygen, ANMEs consume about 70% of methane before it is (…)

In an article published in Nature Structural and Molecular Biology, scientists describe a new structural module at the heart of bacterial energy metabolism. By combining bioinformatics approaches with cutting-edge structural biology techniques, the IBS researchers, in collaboration with the LCB (Bacterial Chemistry Laboratory, Marseille), were able to identify a new structural module: a surprising tubular structure that connects oxidoreductases to the bacterial membrane and thus to (…)

Every year the CNRS rewards the women and men, from its Joint Research Units, who have contributed most significantly to advancing French research and innovation. In 2025, two IBS engineers are honored: Alicia Vallet, a nuclear magnetic resonance study engineer in the IBS NMR group, has been awarded the 2025 CNRS Crystal Medal for her involvement in the Infranalytics national research infrastructure. Meet Alicia Contact Lionel Imbert, research engineer in the NMR Large Assemblies (…)

Cryptochromes are ubiquitous proteins, central to the regulation of the circadian clock. The majority of cryptochromes are light-sensitive and thus also serve as photoreceptors (for blue or red light). Additionally, some cryptochromes act as photoenzymes able to perform DNA damage repair while others are believed to be sensors of the earth’s magnetic field in migratory birds. Despite their ubiquitousness and the exceptional plurality of their function, the mechanisms governing the transition (…)

In response to the alarming rise in antibiotic resistance, the search for new bioactive molecules has become a public health priority. Among the most promising leads are ribosomally-synthesized and post-translationally modified peptides (RiPPs), a diverse family of natural compounds with rich structural complexity and therapeutic potential. In collaboration with a research team from Singapore and scientists from the EDyP laboratory at IRIG (CEA-Grenoble), researchers from the (…)

Photoconvertible fluorescent proteins (PCFPs) like mEos4b shift their fluorescence emission from green to red upon 405 nm illumination, making them essential markers for super-resolution techniques such as Single Molecule Localization Microscopy (SMLM). However, their photophysical properties continue to reveal surprises. Besides photoconversion, PCFPs can reversibly switch between fluorescent and nonfluorescent states. In its red form, mEos4b undergoes “negative switching”: it turns off (…)

EL222 is a light-sensitive protein from the marine bacterium Erythrobacter litoralis that regulates gene expression in response to blue light. This regulation occurs through structural changes triggered by the activation of a small molecule inside the protein, called flavin mononucleotide (FMN). To better understand how EL222 functions, the NMR group of the IBS, and researchers from the Institute of Biotechnology of the Czech Academy of Sciences, investigated chemical and structural (…)

Bacteriophages, viruses infecting bacteria, are the most abundant living entities on Earth. They are present in all ecosystems where bacteria develop and are instrumental in the regulation, diversity, evolution, and pathogeny of microbial populations. Moreover, with the increasing number of pathogenic strains resistant to antibiotics, virulent phages are considered a serious alternative or complement to classical treatments. 96% of all phages present a tail that allows host recognition and (…)

Scaffold proteins are key players in many signaling pathways where they ensure spatial and temporal control of molecular interactions by simultaneous tethering of multiple signaling components. The protein JIP1 acts as a scaffold within the c-Jun N-terminal kinase (JNK) signaling pathway, one of the three main mitogen-activated protein kinase (MAPK) pathways. JIP1 has a long, intrinsically disordered N-terminal domain consisting of 450 amino acids, for which the molecular mechanisms (…)

Every year, fungal infections caused by Candida yeast claim hundreds of thousands of lives worldwide. As antifungal resistance continues to rise, current treatments are becoming less effective, making the search for new therapeutic strategies increasingly urgent. One promising approach targets Bdf1, a fungal protein that plays a key role in gene regulation and is essential for Candida viability. However, developing a Bdf1 inhibitor that selectively targets the fungal protein without (…)

As pathogenic microorganisms have a strong capacity to develop resistance, particularly against new compounds belonging to existing antibiotic families, new anti-infectives with unprecedented mechanisms of action are urgently needed. The biosynthesis of terpenoids represents an attractive source of drug. Terpenoids are essential metabolites produced by the assembly of two precursors. These precursors are produced by two different metabolic pathways: the mevalonate (MVA) pathway and the (…)

A first article published in 2023 proposed an initial model for the encapsidation of Influenza virus genome. In a new publication published in the Nucleic Acids Research journal, the same scientists have now obtained a high-resolution structure of the Influenza nucleoprotein in an antiparallel helix that now details precisely all the protein-protein and protein-RNA interactions within the nucleocapsid. Every year, Influenza virus causes major epidemics affecting between 2 to 6 million (…)

The sexual forms of Plasmodium falciparum (Pf), the causative agent of malaria, are transmitted from humans to mosquitoes, enabling the parasite to spread. It is well established that antibodies (Ac) can efficiently block parasite transmission. To identify the targets of these antibodies, the Complement, antibodies and infectious disease Group developed a high-throughput screening method: after non-specific activation of memory B cells from blood samples, the antibodies produced were (…)