Open AccessLexA, a transcription regulator binding in the promoter region of the bidirectional hydrogenase in the cyanobacterium Synechocystis sp. PCC 6803
Author(s) -
Oliveira Paulo,
Lindblad Peter
Publication year - 2005
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/j.femsle.2005.07.024
Subject(s) - repressor lexa , operon , synechocystis , promoter , biology , transcription (linguistics) , repressor , hox gene , regulon , gene , transcriptional regulation , dna binding protein , binding site , transcription factor , microbiology and biotechnology , genetics , gene expression , linguistics , philosophy , escherichia coli , mutant
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.