GOHL, HP and HAUSNER, W and THOMM, M (1992) CELL-FREE TRANSCRIPTION OF THE NIFH1 GENE OF METHANOCOCCUS-THERMOLITHOTROPHICUS INDICATES THAT PROMOTERS OF ARCHAEAL NIF GENES SHARE BASIC FEATURES WITH THE METHANOGEN CONSENSUS PROMOTER. MOLECULAR & GENERAL GENETICS, 231 (2). pp. 286-295. ISSN 0026-8925,
Full text not available from this repository.Abstract
The nifH1 gene of Methanococcus thermolithotrophicus, which encodes the putative dinitrogenase reductase of an archaeon, was accurately transcribed in a homologous cell-free transcription system. Extracts of cells grown with N2 or ammonia as nitrogen source initated transcription at the nifH1 promoter with similar efficiencies. We confirmed that cells grown under non-N2-fixing conditions do not contain significant amounts of nifH1-specific mRNA. The levels of cell-free transcription initiation at the nifH1 promoter wer similar to those observed at a tRNA promoter. The DNA sequence from -40 to +5 relative to the initiator nucleotide of nifH1 mRNA contained all the information required for promoter activity. A mutational analysis of this section of DNA demonstrated that a TATA box at -25 and the TTGT motif (initiator element) at the transcription start site are essential for cell-free transcription. These elements are similar to the structural determinants of a known tRNA promoter of Methanococcus. Mutation of a sequence, showing homology to the bacterial NifA site, which overlaps the transcription start site, did not affect promoter activity. Hence, cell-free transcription of the Methanococcus nifH1 gene is independent of upstream activator elements and does not require alternate cis-acting sequences that differ from the methanogen consensus promoter. These findings suggest that the activation of nif promoters is brought about by fundamentally different mechanisms in Archaea and bacteria.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | NITROGENASE STRUCTURAL GENES; STABLE RNA GENES; KLEBSIELLA-PNEUMONIAE; ARCHAEBACTERIAL PROMOTER; FIXATION GENES; TATA BOX; SEQUENCES; INVITRO; EXPRESSION; POLYMERASE; ARCHAEA; NITROGEN FIXATION; NIFH PROMOTER; CELL-FREE TRANSCRIPTION; METHANOCOCCUS |
| Depositing User: | Dr. Gernot Deinzer |
| Last Modified: | 19 Oct 2022 08:44 |
| URI: | https://pred.uni-regensburg.de/id/eprint/54722 |
Actions (login required)
 |
View Item |
