title: LexA, a transcription regulator binding in the promoter region of the bidirectional hydrogenase in the cyanobacterium Synechocystis sp. PCC 6803.
abstract: The unicellular cyanobacterium Synechocystis PCC 6803 contains a single pentameric bidirectional hydrogenase encoded by hoxEFUYH. Transcriptional experiments demonstrated that the five hox genes are part of a single transcript together with three ORFs with unknown functions. The transcription start point was localized by 5' RACE to 168bp upstream the hoxE ATG start codon. DNA affinity assays demonstrated a specific interaction between the hox regulatory promoter region and a protein which, using mass spectrometry, was identified to be LexA. Overexpressed His-tagged Synechocystis LexA and EMSA showed a specific binding to the promoter region of the hox operon. Increasing concentrations of the purified LexA resulted in two retarded LexA-DNA complexes, in agreement with the presence of two putative LexA binding sites upstream the determined TSP.
authors.affiliation: Department of Physiological Botany, EBC, Uppsala University, Villavägen 6, SE-752 36 Uppsala, Sweden. Paulo.Oliveira@ebc.uu.se
authors.forename: Paulo
authors.initials: P
authors.lastname: Oliveira
authors.forename: Peter
authors.initials: P
authors.lastname: Lindblad
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D004269:DNA, Bacterial / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D005798:Genes, Bacterial; D006864:Hydrogenase / Q000235:genetics*; D008969:Molecular Sequence Data; D009876:Operon; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D046939:Synechocystis / Q000235:genetics* / Q000378:metabolism; D024363:Transcription Initiation Site; D000099160:LexA Repressor Protein
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D006864:Hydrogenase; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein