An archaebacterial promoter sequence assigned by RNA polymerase binding experiments
| Autor: | Michael Thomm, Gregory S. Beckler, James W. Brown, Bruce A. Sherf, Gerhard Frey, Günter Wich |
|---|---|
| Rok vydání: | 1989 |
| Předmět: |
DNA
Bacterial Transcription Genetic Base pair Immunology Molecular Sequence Data RNA-dependent RNA polymerase RNA polymerase II Euryarchaeota Applied Microbiology and Biotechnology Microbiology chemistry.chemical_compound Transcription (biology) RNA polymerase Genetics RNA polymerase I 570 Biowissenschaften Biologie Promoter Regions Genetic Molecular Biology Polymerase Binding Sites biology Bacteria Base Sequence General Medicine DNA-Directed RNA Polymerases Molecular biology Archaea chemistry Genes Bacterial RNA polymerase binding biology.protein ddc:570 |
| Zdroj: | Canadian journal of microbiology. 35(1) |
| ISSN: | 0008-4166 |
| Popis: | To identify an archaebacterial promoter sequence, nuclease protection studies with the purified RNA polymerase of Methanococcus vannielii were performed. The enzyme binds specifically both at protein-encoding (hisA and methyl CoM reductase, component C) and tRNA–rRNA genes. The binding region of the RNA polymerase extends from 30 base pairs (bp) upstream (−30) to 20 bp downstream (+20) from the in vivo transcription start site. This finding indicates that the archaebacterial enzyme recognizes promoters without transacting traascription factors. The DNA segment protected from nuclease digestion by bound RNA polymerase contains an octanucleotide sequence centered at −25, which is conserved between the protein-encoding and the stable RNA genes. According to the specific binding of the enzyme to only DNA-fragments harbouring this motif, we propose the sequence TTTATATA as the major recognition signal of the Methanococcus RNA polymerase. Comparison of this motif with published archaebacterial DNA sequences revealed the presence of homologous sequences at the same location upstream of 36 genes. We therefore consider the overall consensus [Formula: see text] as a general element of promoters in archaebacteria. In spite of the specific binding of the enzyme, most preparations of the Methanococcus vannielii RNA polymerase are unable to initiate transcription at the correct sites in vitro. Here we present first evidence for the possible existence of a transcription factor conferring the ability to the enzyme to initiate and terminate transcription specifically in vitro.Key words: promoter, footprint, TATA box, RNA polymerase, transcription. |
| Databáze: | OpenAIRE |
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