Cloning and expression of the gene for bacteriophage T7 RNA polymerase
The complete coding sequence of the gene for bacteriophage T7 RNA polymerase (T7 gene 1) has been cloned in the plasmid pBR322. Large amounts of active enzyme can be accumulated in Escherichia coli when the cloned gene is transcribed from the lac UV5 promoter. A protease activity that apparently can nick the protein without causing it to fall apart can be a problem during purification, but a procedure is described that gives good yields of essentially homogeneous, highly active enzyme suitable for biochemical and physical studies. T7 RNA polymerase has a stringent specificity for its own promoters and will selectively transcribe DNA that has been linked to such a promoter. This specificity makes the enzyme useful both for producing specific RNAs in vitro and for directing the expression of selected genes inside the cell. Having the cloned gene also makes possible a detailed mutational analysis of the functioning of T7 RNA polymerase. 25 references, 3 figures.
- Research Organization:
- Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI ID:
- 5932644
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Vol. 81
- Country of Publication:
- United States
- Language:
- English
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Cloning and expression of the gene for bacteriophage T7 RNA polymerase
Cloning and expression of the gene for bacteriophage T7 RNA polymerase
Related Subjects
GENES
CLONING
RNA POLYMERASES
PURIFICATION
BACTERIOPHAGES
DNA
DNA SEQUENCING
ENZYME ACTIVITY
ESCHERICHIA COLI
BACTERIA
ENZYMES
MICROORGANISMS
NUCLEIC ACIDS
NUCLEOTIDYLTRANSFERASES
ORGANIC COMPOUNDS
PARASITES
PHOSPHORUS-GROUP TRANSFERASES
POLYMERASES
STRUCTURAL CHEMICAL ANALYSIS
TRANSFERASES
VIRUSES
550400* - Genetics