A lysR-type regulator is involved in the negative regulation of genes encoding selenium-free hydrogenases in the archaeon Methanococcus voltae.
The archaeon Methanococcus voltae encodes two pairs of NiFe-hydrogenase isoenzymes. One hydrogenase of each pair contains selenium in the active site, whereas the other one is selenium-free. The gene groups for the selenium-free hydrogenases, called vhc and frc, are linked by a common intergenic region. They are only transcribed under selenium limitation. A protein binding to a negative regulatory element involved in the regulation of the two operons was purified by DNA-affinity chromatography. Through the identification of the corresponding gene the protein was found to be a LysR-type regulator. It was named HrsM (hydrogenase gene regulator, selenium dependent in M. voltae). hrsM knockout mutants constitutively transcribed the vhc and frc operons in the presence of selenium. A putative HrsM binding site was also detected in the intergenic region in front of the hrsM gene. Northern blot analysis indicated that the hrsM gene might be autoregulated.
Sun
Junsong
J
Genetics, Department of Biology, Philipps-University of Marburg, D-35032 Marburg, Germany.
Klein
Albrecht
A
D000595:Amino Acid Sequence; D019843:Archaeal Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D019848:Gene Expression Regulation, Archaeal; D006864:Hydrogenase / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D017017:Methanococcus / Q000201:enzymology / Q000235:genetics*; D008969:Molecular Sequence Data; D009876:Operon; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012643:Selenium / Q000032:analysis / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D014162:Transfection
D019843:Archaeal Proteins; D004268:DNA-Binding Proteins; C043296:nickel-iron hydrogenase; D006864:Hydrogenase; D012643:Selenium