Institut de Biologie Structurale

Superinfection exclusion strategy of siphophage T5: analysis of the FhuA:Llp complex

ABSTRACT Superinfection exclusion is a widespread viral mechanism that protects the infected cell from overinfection by other identical or closely related viruses. Shortly after infection by bacteriophage T5, the bacterium Escherichia coli produces Llp, encoded by the newly injec...

Targeting the Complement C1 Proteases Using Camelid-Derived Single Domain Antibodies: Production, Characterization and Possible Application for Tissue/Fluid Analysis

Background. The complement C1r and C1s proteases initiate the classical complement pathway within the C1 complex, but emerging evidence points to additional roles in tissues, including cell-intrinsic functions linked to cancer and connective tissue disorders. Few tools are availa...

Direct Visualization of a Hydroperoxy Intermediate in Fluorescent Protein Chromophore Maturation in PAmCherry1

Abstract Despite the widespread use of fluorescent proteins in bioimaging, the mechanism of oxidative chromophore maturation to form the tyrosine Cα═Cβ double bond remains unclear. In the photoactivatable fluorescent protein PAmCherry1, this double bond has not yet been formed pr...

Molecular mechanism of calcium inhibition in viral channelrhodopsins

Abstract Viral channelrhodopsins (VCR1s) are giant-virus-encoded light-gated channels permeable to monovalent and divalent cations, including Na + and Ca 2+ ions, and inhibited by millimolar Ca 2+ concentrations. Here, we combine X-ray crystallography, time-resolved UV-vis spectr...

Resolving Hidden Stoichiometriesin Bacterial ProteasomeActivator (Bpa)-Substrate Complexes by Cryo-EM and Charge DetectionMass Spectrometry

Abstract Bacterial proteasome activator (Bpa) is a regulatory particle within the Mycobacterium tuberculosis (Mtb) proteasome system that facilitates ATP-independent substrate engagement and delivery to the 20S core particle (CP) for degradation. The best characterized Bpa substr...

The postsynaptic scaffolding protein SAPAP3 shapes mitochondrial activity: the case of Huntington’s disease

Abstract Postsynaptic scaffolding protein SAP90/PSD95-associated protein 3 (SAPAP3) modulates cortico-striatal signalling and regulates the maintenance of synaptic structure. Notably, SAPAP3 defects have been reported in several human psychiatric disorders that share pathophysiol...