Étude structurale du filament des recombinases par des approches de spectroscopie optique et de modélisation moléculaire

La recombinaison homologue est un processus universel d'échange d'un brin d'ADN entre deux molécules de séquences équivalentes. Elle est catalysée par des protéines conservées depuis les phages jusqu'aux hommes : les recombinases (RecA Eubactérienne, RadA Archae et Rad51 Eucaryote). Les recombinases sont actives sous la forme d'un filament formé sur l'ADN simple-brin en présence d'ATP. Elles hydrolysent l'ATP et il existe deux conformations du filament associées à l'état du co-facteur (ATP/ADP). Dans la première partie de ce travail nous avons mis en évidence les similitudes existantes entre les interfaces protéine-protéine des filaments de recombinases eucaryotes, inconnues jusqu'alors, et eubactériennes par une approche de spectroscopie optique. Dans un second temps nous avons mis en place une stratégie de modélisation moléculaire qui nous permet de proposer, pour la première fois, des modèles de chacune des conformations des filaments.Homologous recombination is the universally conserved process of strand exchange between two DNA molecules of similar sequences. It is catalysed by a family of proteins found from phages to human : recombinases (Eubacterian RecA, Archaeal RadA and Eucaryotic Rad51). Recombinases are active as a filament formed on single-strand DNA in the presence of ATP. They hydrolyze ATP and two conformational states of the filament exist, each associated with one type of co-factor (ATP/ADP). In the first part of this work, using optical spectroscopy, we proved that the previously unknown protein-protein interface in the eucaryotic recombinase filament to have similarities to that of eubacterian recombinase. Secondly we computationaly modelled each of the filament conformation. This is the first time that such a model of the two states has been proposed at the molecular scale.NANTES-BU Sciences (441092104) / SudocSudocFranceF

Effect of the Demographic Variables and Psychometric Properties of the Personal Well-Being Index for School Children in India

The Personal Well-being Index-school children (PWI-SC; Cummins and Lau 2005) measures well-being of adolescents. The study aimed at validating psychometric properties for the English and the Hindi translated version of PWI-SC in Indian context. Data from 1,301 students, aged 13–18 years (mean age = 15.40 years, SD = 1.33) was collected. The English and Hindi version confirmed one-factor solution of the PWI-SC. The convergent validity was supported through positive correlations with Flourishing Scale (FS; Diener et al. 2010) and Brief Multidimensional Students Life Satisfaction Scale (BMSLSS; Huebner et al. 2004). The effect of demographic variables on different domains of PWI-SC indicated that adolescents who resided in rural areas and those who attended private school possessed a significantly higher score on PWI-SC. Well-being declined as age increased from early adolescent to middle adolescence to late adolescence. The results of this study are in agreement with the previous literature