Model for the light-harvesting complex I (B875) of Rhodobacter sphaeroides.
The light-harvesting complex I (LH-I) of Rhodobacter sphaeroides has been modeled computationally as a hexadecamer of alphabeta-heterodimers, based on a close homology of the heterodimer to that of light-harvesting complex II (LH-II) of Rhodospirillum molischianum. The resulting LH-I structure yields an electron density projection map that is in agreement with an 8.5-A resolution electron microscopic projection map for the highly homologous LH-I of Rs. rubrum. A complex of the modeled LH-I with the photosynthetic reaction center of the same species has been obtained by a constrained conformational search. This complex and the available structures of LH-II from Rs. molischianum and Rhodopseudomonas acidophila furnish a complete model of the pigment organization in the photosynthetic membrane of purple bacteria.
Beckman Institute and Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 USA.
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D000595:Amino Acid Sequence; D001059:Apoproteins / Q000737:chemistry; D001426:Bacterial Proteins; D019281:Dimerization; D045342:Light-Harvesting Protein Complexes; D008854:Microscopy, Electron; D008958:Models, Molecular; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry* / Q000648:ultrastructure; D017433:Protein Structure, Secondary; D012242:Rhodobacter sphaeroides / Q000378:metabolism*; D012246:Rhodospirillum / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
D001059:Apoproteins; D001426:Bacterial Proteins; D045342:Light-Harvesting Protein Complexes; D045322:Photosynthetic Reaction Center Complex Proteins; C094744:light-harvesting complex 1, Rhodospirillum