Amino acid charge distribution influences the assembly of apoprotein into light-harvesting complex II.
The light-harvesting complex II of thylakoid membranes channels light energy into the photosynthetic reaction center II. The major apoproteins of this complex are the nuclear encoded light-harvesting chlorophyll a/b-proteins (LHCP). A model for the arrangement of LHCP in the thylakoid membrane predicts three alpha-helical membrane-spanning regions. The first and third putative membrane-spanning regions include oppositely charged amino acid residues. When the first and third helices are altered to carry only positive charges, the in vitro accumulation of LHCP in the complex is reduced. This mutation is partially rescued by the introduction of a new negative charge in the third helix, an arrangement that is reversed from the wild type. An arginine in the first helix is also important in some aspect of the process leading to the successful accumulation of the LHCP in thylakoids.
Kohorn
B D
BD
Biology Department, University of California, Los Angeles 90024.
Tobin
E M
EM
D000596:Amino Acids; D001051:Apoenzymes / Q000235:genetics*; D001059:Apoproteins / Q000235:genetics*; D001483:Base Sequence; D002736:Chloroplasts / Q000201:enzymology; D004262:DNA Restriction Enzymes; D042963:Electron Transport Complex II; D008027:Light; D009097:Multienzyme Complexes / Q000235:genetics*; D009154:Mutation; D010088:Oxidoreductases / Q000235:genetics*; D010944:Plants / Q000201:enzymology*; D011487:Protein Conformation; D013385:Succinate Dehydrogenase / Q000235:genetics*
D000596:Amino Acids; D001051:Apoenzymes; D001059:Apoproteins; D009097:Multienzyme Complexes; D010088:Oxidoreductases; D042963:Electron Transport Complex II; D013385:Succinate Dehydrogenase; D004262:DNA Restriction Enzymes