This project concerned two nuclear genes in maize, crp1 and atp1, whose function is required for the translation of one or several chloroplast mRNAs. Mutations in these genes cause a reduction in the number of ribosomes bound to the regulated mRNAs, implying a defect in translation initiation or early elongation. The proposed experiments were designed to elucidate how their gene products activate translation. The specific aims of the proposal were to: 1. Identify biochemical activities associated with purified native and recombinant Crp1p; 2. Further optimize the maize chloroplast in vitro translation system; 3. Explore the role of the other components of the Crp1p complex; and 4. Clone the atp1 gene and initiate functional studies of its gene product. Because CRP1 biochemistry proved to be intractable because of its insolubility after expression in E. coli, we modified the original aims to include an exploration of the functions of other members of the PPR family. The hope was that other members of the family would be more amenable to biochemical analysis than CRP1. Thus, we used reverse genetic approaches to determine the in vivo roles of two other chloroplast-localized PPR proteins.
PDF
download
878987797
028-85220240
