A chloroplast RNA binding protein from stromal thylakoid membranes specifically binds to the 5' untranslated region of the psbA mRNA.
The intrachloroplastic localization of post-transcriptional gene expression steps represents one key determinant for the regulation of chloroplast development. We have characterized an RNA binding protein of 63 kDa (RBP63) from Chlamydomonas reinhardtii chloroplasts, which cofractionates with stromal thylakoid membranes. Solubility properties suggest that RBP63 is a peripheral membrane protein. Among RNA probes from different 5' untranslated regions of chloroplast transcripts, RBP63 preferentially binds to the psbA leader. This binding is dependent on a region comprising seven consecutive A residues, which is required for D1 protein synthesis. A possible role for this newly discovered RNA binding protein in membrane targeting of psbA gene expression is discussed.
Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany.
Friedrich
F
Ossenbühl
Kristina
K
Hartmann
Jörg
J
Nickelsen
D020121:5' Untranslated Regions / Q000378:metabolism*; D000818:Animals; D001665:Binding Sites; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D046911:Macromolecular Substances; D008970:Molecular Weight; D045322:Photosynthetic Reaction Center Complex Proteins / Q000235:genetics*; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000302:isolation & purification* / Q000378:metabolism; D011485:Protein Binding; D025941:Protein Interaction Mapping; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000302:isolation & purification* / Q000378:metabolism; D018749:RNA, Plant / Q000378:metabolism*; D016053:RNA, Protozoan / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000302:isolation & purification* / Q000378:metabolism; D020524:Thylakoids / Q000737:chemistry*
D020121:5' Untranslated Regions; D046911:Macromolecular Substances; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D015800:Protozoan Proteins; D018749:RNA, Plant; D016053:RNA, Protozoan; D016601:RNA-Binding Proteins