Plastid RNA polymerases

Abstract

Plastids have a very interesting transcription apparatus that gives us an opportunity to investigate mono- and multisubunut RNA polymerase interaction under conditions of complex biogenesis of the organelles and the necessity to coordinate the expression of genes located in different cell compartments. The last decade has been a breakthrough in the study of chloroplast RNA polymerases. The most important advances are the discovery of nucleus-encoded RNA polymerase and nuclear gene family for sigma subunits of plastid-encoded RNA polymerase, the obtaining of knockout-mutants on the subunits of plastid-encoded RNA polymerase, and the revelation of this RNA polymerase reorganization during plastid biogenesis. The hypothesis concerning labor division between two plastid RNA polymerases has been proposed. The review focuses on the analysis of modem information about organization, function and evolution of plastid RNA polymerases.