What is Expression vector?
Vector is a DNA molecule which is used as a vehicle that carry foreign genetic material which is artificially prepared into another cell. And in another cell it can be replicated or expressed.
If it is replicated which means producing many copies of the targetted gene then it is called as cloning vector.
Expression vector is used for the gene expression. The gene we inserted has to be expressed. Expression in simple terms is defined as gene has to produce the protein. First, gene produce mRNA and then mRNA is translated to protein.
Expression vector makes the host cell to produce gene product. It has gene expression machinery which is not present in cloning vectors.
Expression vectors must have sequence for expression of desired protein such as ribosomal binding site which is used for ribosome binding, promoter, Kozak sequences in eukaryotes or the Shine Dalgarno sequence for prokaryotes etc.