Alessandro Valeri

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Two complementary methods in confocal single-molecule fluorescence spectroscopy are presented to analyze conformational dynamics by Forster resonance energy transfer (FRET) measurements considering simulated and experimental data. First, an extension of photon distribution analysis (PDA) is applied to characterize conformational exchange between two or more(More)
The nucleosome has a central role in the compaction of genomic DNA and the control of DNA accessibility for transcription and replication. To help understanding the mechanism of nucleosome opening and closing in these processes, we studied the disassembly of mononucleosomes by quantitative single-molecule FRET with high spatial resolution, using the(More)
In the recent decade, single-molecule (sm) spectroscopy has come of age and is providing important insight into how biological molecules function. So far our view of protein function is formed, to a significant extent, by traditional structure determination showing many beautiful static protein structures. Recent experiments by single-molecule and other(More)
Probability distribution analysis (PDA) [M. Antonik et al., J. Phys. Chem. B 2006, 110, 6970] allows one to quantitatively analyze single-molecule (SM) data obtained in Forster resonance energy transfer (FRET) or fluorescence polarization experiments. By taking explicitly background and shot noise contributions into account, PDA accurately predicts the(More)
An analysis method of lifetime, polarization and spectrally filtered fluorescence correlation spectroscopy, referred to as filtered FCS (fFCS), is introduced. It uses, but is not limited to, multiparameter fluorescence detection to differentiate between molecular species with respect to their fluorescence lifetime, polarization and spectral information.(More)
The 3D folding of the genome and its relation to fundamental processes such as gene regulation, replication, and segregation remains one of the most puzzling and exciting questions in genetics. In this review, we describe how the use of new technologies is starting to revolutionize the field of chromosome organization, and to shed light on the mechanisms of(More)
Bacteria have evolved complex, highly-coordinated, multi-component cellular engines to achieve high degrees of efficiency, accuracy, adaptability, and redundancy. Super-resolution fluorescence microscopy methods are ideally suited to investigate the internal composition, architecture, and dynamics of molecular machines and large cellular complexes. These(More)
Chromatin insulators are factors involved in higher-order, genome-wide organization of chromatin, and play key roles in regulating transcriptional programs. In this review, we discuss recent studies on the diverse composition of insulator complexes, and on the mechanism by which they establish long-range DNA interactions. Particularly, we describe new(More)
1 ​Centre de Biochimie Structurale, CNRS UMR5048, INSERM U1054, Université de Montpellier, 29 rue de Navacelles, 34090 Montpellier, France 2​ CNAG-CRG, Centre for Genomic Regulation (CRG), Barcelona Institute of Science and Technology (BIST), Baldiri i Reixac 4, 08028 Barcelona, Spain; Gene Regulation, Stem Cells and Cancer Program, Centre for Genomic(More)