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Gonzalez Aleman, R.

Publications and source records attributed to Gonzalez Aleman, R..

2 recordsLinked to original sources

Communication pathway analysis within protein-nucleic acid complexes

Inter-residue communication forms a vast and intricate network that underpins essential biological processes such as catalysis, gene expression, and cell signaling. Allostery, a crucial phenomenon where distant regions of a macromolecule are energetically coupled to elicit functional responses, operates through these intricate communication networks within macromolecular complexes. Despite the pivotal role of nucleic acids in these networks, their contributions to allostery remain largely overlooked. To address this gap, we developed ComPASS, a large-scale computational method designed to study communication networks in protein-protein and protein-nucleic acid complexes. Recognizing the significance of dynamics in the communication of macromolecules, our approach leverages molecular dynamics (MD) simulation data to extract inter-residue key properties, including dynamical correlations, interactions, and distances. These properties are integrated to construct a weighted communication network that comprehensively represents dependencies among amino acids and nucleotides. Using ComPASS, we uncovered distinct mechanisms of signal transmission in diverse macromolecular systems. In Cysteinyl-tRNA synthetase, the central domain was found to mediate the coordination between substrate recognition and enzymatic activity, ensuring functional precision. In the LacI repressor, allosteric communication occurs through interface pathways within the dimer, effectively linking ligand sensing to DNA binding. For the Type IIF restriction endonuclease Bse634I, structural communication across dimer and tetramer interfaces was crucial for specific DNA recognition. In the liver X receptor, a key helical region was identified as a bridge connecting ligand-binding events to DNA interactions. Finally, our analysis with ComPASS aligned with previous literature, confirmed the role of H2A L1 loops in mediating communication across histone interfaces and coordinating interactions between structural domains in nucleosome complexes. ComPASS is available as an open-source tool, maintained at https://github.com/yasamankarami/compass. By offering an integrated framework for studying communication networks, ComPASS advances our understanding of conformational dynamics, particularly within protein-nucleic acid complexes.

bioinformatics↗

Histone H3 as a redox switch in the nucleosome core particle: insights from molecular modeling

Histones post-translational modifications are major regulators of the chromatin dynamics. Understanding the structural signature of these marks in the nucleosome context is of major importance to unravel their mechanisms of action and open perspectives for the development of new therapies. In this work, we rely on multi-microseconds molecular dynamics simulations and advanced structural analysis to unravel the effect of two modifications of the histone H3: S-sulfenylation and S-nitrosylation. These oxidative modifications are known to target the cysteine 110 on the histone H3, but there their effect on the nucleosome dynamics. In this study, we show that in a nucleosome core particle, S-sulfenylation and S-nitrosylation exhibit different structural signatures, which suggests that they play a different function. While S-sulfenylation destabilizes DNA-histone communication at the dyad and could be linked to the promotion of nucleosome disassembly events, S-nitrosylation exhibits a mild effect on the nucleosome dynamics and might have a different function. Our results highlight the fine tune link between the chemical nature of histone core post-translational modifications and their impact on the nucleosomes large architecture. We provide new insights into the regulatory mechanisms of histone oxidative modifications, about which very little is known so far.

biophysics↗