Is the T7 terminator transcribed?
Is the T7 terminator transcribed?
The phage-derived T7 RNA polymerase is the most prominent orthogonal transcriptions system used in the field of synthetic biology. However, gene expression driven by T7 RNA polymerase is prone to read-through transcription due to contextuality of the T7 terminator.
What kind of structure does the terminator sequence form?
hairpin
The terminator DNA sequence encodes a region of RNA that folds back on itself to form a hairpin. The hairpin is followed by a series of U nucleotides in the RNA (not pictured).
How does T7 promoter work?
T7 RNA polymerase is a very active enzyme: it synthesizes RNA at a rate several times that of E. coli RNA polymerase and it terminates transcription less frequently; in fact, its transcription can circumnavigate a plasmid, resulting in RNA several times the plasmid length in size.
What is T7 protein expression?
The T7 expression system allows high-level expression from the strong bacteriophage T7 promoter. It’s ideal for expressing soluble, nontoxic recombinant proteins in E. coli. The T7 expression vectors are designed to facilitate cloning using Gateway® technology, and easy protein purification and detection.
How does T7 terminator work?
The bacteriophage T7 terminator (T7-T phi) encodes an RNA sequence that can form a stable stem-loop structure followed by a run of six uridylate residues; termination occurs at a 3′ G residue just downstream of the U run.
What is rrnB terminator?
The termination region of the rrnB gene coding for ribosomal RNA in Escherichia coli is large and complex. It contains two regions (T1 and T2) with typical factor-independent terminator-like sequences, two additional inverted repeats (lR1 and IR2) and a pair of direct repeats.
Where are terminator sequences found?
Terminator sequences are found close to the ends of noncoding sequences (Figure 2c). Bacteria possess two types of these sequences.
What is a terminator region?
The terminator region, on the other hand, is the nucleotide sequence that determines the detachment of RNA polymerase from the DNA template strand, which occurs towards the end of the transcription process.
How does T7 expression work?
T7 expression hosts such as DE3 prophage strains or T7 Express strains carry a chromosomal copy of the phage T7 RNA polymerase gene. When inducer is added, T7 RNA polymerase is expressed and becomes dedicated to target gene transcription.
