Ampicillin resistance genes

Figure 26-7 Genetic map of cloning plasmids pBR322 and pUC18. Abbreviations ori, origin of replication Amp1, ampicillin resistance gene Tet1, tetracycline resistance gene. Other abbreviations are for sites cleaved by specific restriction endonucleases, a few of which are defined in Table 26-2. The nucleotide sequence numbers and directions of transcription are also indicated. Reproduced by permission of Amersham Pharmacia Biotech Inc.

Plasmids containing the cyanobacterial CA gene icfk) [3], promoter and terminator derived from RuBisCO and the ampicillin resistant gene were constructed (Fig.2). The resulting plasmids were introduced into Synechococcus sp. PCC7942 [4]. 

The pUC vectors contain an ampicillin-resistance gene and a multiple cloning site at the 5 -end of the lacZ gene. Insertional inactivation of lacZ allows... 

The pWHA43 plasmid contains 3.9 kbp and replicates with the pMBl origin of replication. The plasmid was constructed with an insert of cDNA encoding met-prochymosin under the control of a tandem lac-trp promotor operator arrangement as described in (1). The prochymosin gene was inserted just upstream from the ampicillin resistance gene without a transcription terminator sequence between, but with the RNA polymerase binding site for amp also intact, so that presumably amp is transcribed from both the lac-trp and natural amp promotors. 

This chapter will not focus on the recombinant DNA techniques used to construct plasmids encoding recombinant toxins, since such methods are not unique to recombinant toxins. The method described for plasmid expression in E. coli BL21/A.DE3 cells is applicable for plasmids containing the T7 promoter (14) and the ampicillin resistance gene. 

To clarify whether this stability was due to integrative transformation, we examined the cellular DNA of AlO-14 by Southern blot analysis. The result indicated that most of the DNA of pHDVl 1, with the exception of a small deleted region of the ApA (ampicillin resistance) gene, was integrated as a sirtgle copy in the chromosome. 

Fig. 3. Siie-directed mutagenesis of RBP cDNA. R, reverse primer F, forward primer M, mutagenic primer RBS, ribosome-binding site Omp, OmpA signal sequence Amp ampicillin-resistance gene.

If the insert and the plasmid are the same size, we digest the ampicillin resistance gene with Seal to cut the plasmid into two pieces. 

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