In vitro synthesis and assembly of photosystem II proteins of spinach chloroplasts.
The synthesis and assembly of photosystem II (PS II) proteins of spinach chloroplasts were investigated in three different in vitro systems, i.e., protein synthesis in isolated chloroplasts (in organello translation), read-out translation of thylakoid-bound ribosomes, and transport of translation products from spinach leaf polyadenylated RNA into isolated chloroplasts. Polyacrylamide gel electrophoresis of labeled thylakoid polypeptides in the presence of sodium dodecyl sulfate revealed that the first two systems were capable of synthesizing the reaction center proteins of PS II (47 and 43 kDa), the herbicide-binding protein, and cytochrome b559. The reaction center proteins synthesized in organello were shown to bind chlorophyll and to assemble properly into the PS II core complex. One of the reaction center proteins translated by the thylakoid-bound ribosomes (47 kDa) was also found to be integrated in situ into the complex but was lacking bound chlorophyll. Incorporation of radioactivity into the three extrinsic proteins of the oxygen-evolution system (33, 24, and 18 kDa) was detected only when intact chloroplasts were incubated with the translation products from polyadenylated RNA, showing that these proteins are coded for by nuclear DNA. The occurrence of a precursor polypeptide 6 kDa larger than the 33-kDa protein was immunochemically detected in the translation products.
E
E
Minami
K
K
Shinohara
T
T
Kuwabara
A
A
Watanabe
D001692:Biological Transport; D002734:Chlorophyll / Q000032:analysis / Q000096:biosynthesis* / Q000378:metabolism; D002736:Chloroplasts / Q000378:metabolism*; D003573:Cytochrome b Group / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D010788:Photosynthesis; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins / Q000032:analysis / Q000096:biosynthesis*; D011061:Poly A / Q000378:metabolism; D014176:Protein Biosynthesis; D012313:RNA / Q000378:metabolism; D012333:RNA, Messenger; D012270:Ribosomes / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate; D014675:Vegetables
D003573:Cytochrome b Group; D045342:Light-Harvesting Protein Complexes; D008565:Membrane Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045332:Photosystem II Protein Complex; D010940:Plant Proteins; D012333:RNA, Messenger; C021261:thylakoid polypeptides; D002734:Chlorophyll; D011061:Poly A; D012967:Sodium Dodecyl Sulfate; D012313:RNA; C019313:cytochrome b559; D008715:Methionine