title: Role of the fnrL gene in photosystem gene expression and photosynthetic growth of Rhodobacter sphaeroides 2.4.1.
abstract: Anoxygenic photosynthetic growth of Rhodobacter sphaeroides 2.4.1 requires a functional fnrL gene, which encodes the anaerobic regulator, FnrL. Using transcriptional fusions to the puc operon in which the upstream FNR consensus-like sequence is either present or absent, we obtained results that suggest that FnrL has both a direct and an indirect role in puc operon expression. In addition to FnrL, several other factors, including the two-component Prr regulatory system and the transcriptional repressor PpsR, are known to mediate oxygen control of photosynthesis gene expression in this organism. Therefore, we examined the relationship between FnrL and these other regulatory elements. Our results indicate that while mutations of prr or ppsR can lead to an increase in expression of some photosynthesis genes under aerobic and anaerobic conditions, regardless of the presence or absence of FnrL, there remains an absolute requirement for a functional fnrL gene for photosynthetic growth. We examined the potential role(s) of FnrL in photosynthetic growth by considering several target genes which may be required for this growth mode.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, 77030, USA.
authors.forename: J H
authors.initials: JH
authors.lastname: Zeilstra-Ryalls
authors.forename: S
authors.initials: S
authors.lastname: Kaplan
mesh_terms: D000332:Aerobiosis; D000483:Alleles; D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003227:Conjugation, Genetic; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D009876:Operon; D010749:Phosphoprotein Phosphatases / Q000235:genetics; D010788:Photosynthesis / Q000235:genetics; D010957:Plasmids; D011401:Promoter Regions, Genetic; D011494:Protein Kinases / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000235:genetics; D011995:Recombination, Genetic; D012097:Repressor Proteins / Q000235:genetics; D012242:Rhodobacter sphaeroides / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D015534:Trans-Activators; D001616:beta-Galactosidase / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C096744:FnrL protein, Rhodobacter sphaeroides; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D011494:Protein Kinases; D000071677:Histidine Kinase; D010749:Phosphoprotein Phosphatases; D001616:beta-Galactosidase