MCQ 5 Flashcards
(18 cards)
Expression vector
Plasmid or virus designed specifically to facilitate the expression of a gene of interest in a target cell.
T7 promoter
Strong bacterial promoter used in expression vectors by T7 RNA polymerase leading to high levels of transcription.
PolyA signal in mammalian cells
Signals the transcription machinery to add polyadenylate tails to mRNA.
Selectable marker
Genes included in expression vectors that confer resistance to antibiotics or other toxins.
Enhancer sequence in mammalian expression vectors
Regulatory DNA sequences that, when included in expression vetors can significantly increase the rate of transcription.
Inducible vector
A vector that includes a system where the expression of a gene of interest is controlled by an external stimulus, typically a chemical inducer or a change in environmental conditions.
Lac operon
Promoter and operator sequence that controls the expression of genes involved in lactose metabolsim.
IPTG
Chemical analog of lactose that is not degraded by beta-galactosidase.
BL21 strain
Most common strain of E. coli used because it lacks certain proteases that degrade recombinant proteins.
Inducer in expression vectors
A substance used to activate the expression of a gene from an inducible promoter within an expression vector.
T7 bacteriophage promoter
Phage used for high level expression of cloned genes in E. coli, using T7 RNA polymerase.
Mammalian cells in expression
They can be designed for eukaryotic protein production where folding, and other PTMs are required.
Fusion tags
Short sequence of amino acids or a small protein added to the gene of interest in an expression vector to facilitate purification, detection or solubility of the recombinant protein.
pET system in recombinant protein expression
Uses T7 promoter to drive high level expression in a cloned gene.
Advantages of mammalian inducible expression systems
Minimalized cytotoxic effects from continuous expression.
SV40 region of replication
Area of mammalian gene that allows a plasmid to replicate outside of genomic DNA replication.
Gateway cloning technology
Facilitates DNA insertion into multiple expression vectors allowing easy transfer of GOI.
Yeast two-hybrid system
Molecular tool used to study protein-protein interactions within a yeast expression vector system, highlighting interaction dynamics that can influence gene expression outcomes.
