Analyse des intéractions moléculaires entre deux protéines liant des histones, HIRA et HIRIP3 (HIRA-interacting protein 3) et leur partenaires respectifs, la protéine chaperon d'histones Asf1 et la sérine-thréonine kinase CK2

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocPARIS-BIUP (751062107) / SudocSudocFranceF

Structural Insights into TCTP and Its Interactions with Ligands and Proteins

International audienc

Structural Insights into TCTP and Its Interactions with Ligands and Proteins

International audienc

HIRIP3 is a nuclear phosphoprotein interacting with and phosphorylated by the serine-threonine kinase CK2.

International audienceThe HIRIP3 protein had been identified from its interaction with the HIRA histone chaperone. Experiments using anti-peptide antisera indicated that this 556-aa protein is nuclear throughout the cell cycle and excluded from condensed chromatin during mitosis. Based on its electrophoretic migration and sensitivity to phosphatase treatment, endogenous HIRIP3 was found to be heavily phosphorylated. HIRIP3 can be phosphorylated in vitro by a recombinant form of the serine-threonine kinase CK2. Moreover, HIRIP3 protein was found to co-purify with a CK2 activity. Together, these data prompt us to propose HIRIP3 as a new member of the growing list of CK2 substrates with a possible role in chromatin metabolism

Protein cages: structure, dynamic and function from an integrative structural biology approach

International audienceEnzymes encapsulation inside shell-forming protein cages represents a powerful strategy for controlling catalytic activity in living organisms due to the reaction pathways can be restricted to specific compartments (e.g. the encapsulins are widespread examples in the prokaryotic realm).Hence, the goals of my research aims to understand, the structural relation between the encapsulins protein cages and their encapsulated proteins at atomistic level, shed light over the atomistic details of the capsid stability and also find new small molecules (drug-like) that can interfere the multimeric self-assembly equilibria in order to reach a biomedical and biotechnological impact. My research will be performed under an integrative structural biology framework combining NMR, biochemistry and biophysical experiments as well as computational simulations

Impact of A90P, F106L and H64V mutations on neuroglobin stability and ligand binding kinetics

International audienc

Structural Insights into the Dimeric Form of Bacillus subtilis RNase Y Using NMR and AlphaFold

RNase Y is a crucial component of genetic translation, acting as the key enzyme initiating mRNA decay in many Gram-positive bacteria. The N-terminal domain of Bacillus subtilis RNase Y (Nter-BsRNaseY) is thought to interact with various protein partners within a degradosome complex. Bioinformatics and biophysical analysis have previously shown that Nter-BsRNaseY, which is in equilibrium between a monomeric and a dimeric form, displays an elongated fold with a high content of α-helices. Using multidimensional heteronuclear NMR and AlphaFold models, here, we show that the Nter-BsRNaseY dimer is constituted of a long N-terminal parallel coiled-coil structure, linked by a turn to a C-terminal region composed of helices that display either a straight or bent conformation. The structural organization of the N-terminal domain is maintained within the AlphaFold model of the full-length RNase Y, with the turn allowing flexibility between the N- and C-terminal domains. The catalytic domain is globular, with two helices linking the KH and HD modules, followed by the C-terminal region. This latter region, with no function assigned up to now, is most likely involved in the dimerization of B. subtilis RNase Y together with the N-terminal coiled-coil structure

Conformational Ensemble and Biological Role of the TCTP Intrinsically Disordered Region: Influence of Calcium and Phosphorylation

International audienc

New insights into structural disorder in human respiratory syncytial virus phosphoprotein and implications for binding of protein partners

Phosphoprotein is the main cofactor of the viral RNA polymerase of Mononegavirales. It is involved in multiple interactions that are essential for the polymerase function. Most prominently it positions the polymerase complex onto the nucleocapsid, but also acts as a chaperone for the nucleoprotein. Mononegavirales phosphoproteins lack sequence conservation, but contain all large disordered regions. We show here that Nand Cterminal intrinsically disordered regions account for 80% of the phosphoprotein of the respiratory syncytial virus. But these regions display marked dynamic heterogeneity. Whereas almost stable helices are formed C terminally to the oligomerization domain, extremely transient helices are present in the N terminal region. They all mediate internal long range contacts in this non globular protein. Transient secondary elements together with fully disordered regions also provide protein binding sites recognized by the respiratory syncytial virus nucleoprotein and compatible with weak interactions required for the processivity of the polymerase

Structural Basis for Morpheein-type Allosteric Regulation of Escherichia coli Glucosamine-6-phosphate Synthase

International audienc