title: Sequence of the core antenna domain from the anoxygenic phototroph Heliophilum fasciatum: implications for diversity of reaction center type I.
abstract: Broad variation among anoxygenic reaction centers makes it essential to consider a wide variety when considering the origins of photosynthesis. The photosynthetic core antenna domain in the gene pshA from Heliophilum fasciatum was sequenced doubling the number of core sequences available from heliobacteria. The sequence shares a pattern of hydrophobicity and histidine residues with the core antenna domain of pshA from Heliobacillus mobilis. Sequence identity between the two pshA sequences was 68%, indicating heliobacterial reaction centers show similar diversity to photosystem I throughout cyanobacteria and plastids. Thus, the diversity of anoxygenic phototrophic reaction centers may be greater than previously thought.
authors.affiliation: Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. lmix@oeb.harvard.edu
authors.forename: Lucas J
authors.initials: LJ
authors.lastname: Mix
authors.forename: Tara L
authors.initials: TL
authors.lastname: Harmer
authors.forename: Colleen M
authors.initials: CM
authors.lastname: Cavanaugh
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000302:isolation & purification; D005798:Genes, Bacterial; D006094:Gram-Positive Bacteria / Q000737:chemistry / Q000235:genetics*; D006639:Histidine / Q000235:genetics; D057927:Hydrophobic and Hydrophilic Interactions; D045342:Light-Harvesting Protein Complexes / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D010788:Photosynthesis / Q000235:genetics; D045331:Photosystem I Protein Complex / Q000235:genetics; D018524:Phototropism / Q000235:genetics*; D011166:Porphyrins / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017385:Sequence Homology
chemical_list: D004269:DNA, Bacterial; D045342:Light-Harvesting Protein Complexes; D045331:Photosystem I Protein Complex; D011166:Porphyrins; D006639:Histidine