Examples of " E . coli " expression vectors are the pGEX series of vectors where glutathione S-transferase is used as a fusion partner and gene expression is under the control of the tac promoter, and the pET series of vectors which uses a T7 promoter.
32.
The Sh " ble " gene product binds the antibiotic in a one-to-one ratio so it can no longer cause cleavage of DNA . This resistance gene is used as a selectable marker in some cloning and expression vectors where zeocin is used as the antibiotic for selection.
33.
"Nde " I is useful in generating heterologous DNA construct because it contains the start codon ATG . It therefore can be in used in some expression vectors, such as those in the pET series of vectors, for the ligation of the start of a gene when making an expression construct.
34.
An expression vector has features that any Escherichia coli ", and vectors used for protein production in organisms other than " E . coli " may have, in addition to a suitable origin of replication for its propagation in " E . coli ", elements that allow them to be maintained in another organism, and these vectors are called shuttle vectors.
