Abstract
Plastids are surrounded by two membrane layers, designated as the outer and inner envelope membranes, which have various transport and metabolic activities. We have identified and characterized a novel class of inner envelope membrane proteins, designated as Cor413 inner envelope membrane group (Cor413im). Previously, we showed that Cor413im proteins are integral membrane protein and targeted to the chloroplast envelope both in vitro and in vivo. Cor413im proteins are predicted to have multiple transmembrane segments. However, the targeting mechanism of polytopic envelope membrane proteins remains to be characterized. In this study, we investigated the targeting mechanism of Cor413im to the chloroplast envelope by sucrose density gradient centrifugation and sodium carbonate extraction. We will discuss the possible targeting mechanism of Cor413im to the chloroplast envelope membrane.
