Decrypting the codes for nuclear control of gene expression in organelles
Conférence organisée par le laboratoire SABNP.
Par Charles ROBERT
Laboratoire de Biochimie Théorique
Institut de Biologie Physico Chimique
Le 27 janvier à 14h
Bâtiment Maupertuis - salle 02 W34
3 rue du Père Jarlan - Evry
Mitochondria and chloroplasts in eukaryotic cells arose from endosymbiosis of primitive prokaryotes more than a billion years ago. Along the course of evolution, the cell nucleus gradually assumed control of their gene expression, employing nuclear-encoded proteins that enter the organelle and bind their mRNA sequence-specifically. These proteins fold with an alpha-solenoid architecture comprised of tandem repetitions of degenerate 35-residue (pentatricopeptide repeat, or PPR) or 38-residue (octotricopeptide repeat, or OPR) motifs. In the last fifteen years or so, researchers have identified important determinants of specific recognition in these systems, but the resulting recognition "codes" are incomplete. The first results of our recent collaboration coupling comparative genomics of micro-algae and molecular dynamics simulation suggest new avenues towards refining the PPR- and OPR-mRNA recognition codes and better understanding of the coevolution of the nuclear and chloroplast genomes in eukaryotic organisms.