title: The photosystem I-like P840-reaction center of green S-bacteria is a homodimer.
abstract: An operon encoding the P840 reaction center of Chlorobium limicola f.sp.thiosulfatophilum has been cloned and sequenced. It contains two structural genes coding for proteins of 730 and 232 amino acids. The first protein resembles the large subunits of the Photosystem I (PS I) reaction center. Putative binding elements for the primary donor, P840 in Chlorobium and P700 in PS I and for the acceptors A(o), A(1) and FeS-center X are conserved. The second protein is related to the PS I subunit carrying the FeS-centers A and B. Since all our efforts to find a gene for a second, large subunit failed, the P840 reaction center probably is homodimeric.
authors.affiliation: Universität Regensburg, Lehrstuhl für Zellbiologie und Pflanzenphysiologie, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Büttner
authors.forename: D L
authors.initials: DL
authors.lastname: Xie
authors.forename: H
authors.initials: H
authors.lastname: Nelson
authors.forename: W
authors.initials: W
authors.lastname: Pinther
authors.forename: G
authors.initials: G
authors.lastname: Hauska
authors.forename: N
authors.initials: N
authors.lastname: Nelson
mesh_terms: D000595:Amino Acid Sequence; D001419:Bacteria / Q000737:chemistry / Q000235:genetics*; D003001:Cloning, Molecular; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000235:genetics*; D045331:Photosystem I Protein Complex; D011487:Protein Conformation
chemical_list: D008565:Membrane Proteins; D045322:Photosynthetic Reaction Center Complex Proteins; D045331:Photosystem I Protein Complex