ISSN:
1574-6968
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
The rpoA gene, encoding the α subunit of RNA polymerase, was isolated from alkaliphilic Bacillus sp. strain C-125 by the PCR method. A 3-kb HindIII fragment containing the complete rpoA gene was cloned and sequenced. The α subunit gene was found to encode a protein consisting of 314 amino acid residues with a molecular mass of 34 805 Da. Compared with the amino acid sequences of other known eubacterial RNA polymerase α subunits, the gene has 84% identity to that of B. subtilis, while showing 48% and 47% identity to that of Streptomyces coelicolor and Escherichia coli, respectively. Six conserved regions, which are observed in the case of other eubacteria, were found in the RNA polymerase α subunit of this strain. Five of them are located in the N-terminal domain involved in assembly of the core enzyme, while one is located in the C-terminal domain, which interacts with several transcriptional factors and a specific DNA element. By means of recombinant plasmids, a hexahistidine-tagged derivative of the RNA polymerase α subunit of strain C-125 and two deletion derivatives (C- and N-terminal domains) of this protein were overexpressed in E. coli cells and purified to near homogeneity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1574-6968.1998.tb13283.x
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