title: DNA sequence and in vitro expression of the B875 light-harvesting polypeptides of Rhodobacter sphaeroides.
abstract: The genes for the Rhodobacter sphaeroides light-harvesting B875-beta, and B875-alpha polypeptides (pufB and pufA) are closely linked to the genes for the reaction center L and reaction center M polypeptides (pufL and pufM) on what has been termed the puf operon (gene order, pufB, A, L, M). The DNA sequence of the pufB and pufA structural genes from wild-type R. sphaeroides 2.4.1 was determined and aligned with the available amino acid sequence of the wild-type B875-beta and B875-alpha polypeptides. The relative levels of the B875-beta and B875-alpha and the reaction center L and reaction center M polypeptides synthesized in a homologous cell-free transcription-translation system were compared with those found in vivo. Analysis of the gene products produced in vitro with plasmids containing deletions upstream of the pufB structural gene identified a region of DNA required for expression of the B875-beta and B875-alpha polypeptides. These results support the hypothesis that the mapped 5' termini of the large and small puf operon transcripts represent transcription initiation sites.
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D004262:DNA Restriction Enzymes; D004269:DNA, Bacterial / Q000235:genetics; D005796:Genes; D005798:Genes, Bacterial; D045322:Photosynthetic Reaction Center Complex Proteins; D010957:Plasmids; D014176:Protein Biosynthesis; D012242:Rhodobacter sphaeroides / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D045322:Photosynthetic Reaction Center Complex Proteins; D004262:DNA Restriction Enzymes