Question

A.) Which sequence, genomic or cDNA, would you use to clone into an expression vector in order to produce a human protein in an E.coli host? Explain why (one sentence should do it).    

B.)The C. botulinum (the bacteria causing botulism) genome is 30% G/C base pairs. What is the average distance between BamHI restriction enzyme sites in the genome?

BamHI recognition site is:    G G A T C C

C C T A G G

                                                                                                                       

Answer 1

Ans a) The sequence which would be cloned in an expression vector and is used for production of human protein in E.Coli host will be a cDNA. The cDNA is produced through reverse transcription process from mRNA template and this is used in expression vectors and they are used for gene expression in cells and hence they can be used to insert a specific type of gene within the target cell. As the genomic DNA cannot be directly expressed in E.Coli, hence the expression needs to be inserted with cDNA and this enables expression of the gene within the host. Since the cDNA consists only the coding sequence, its insertion within the expression vector can be directly expressed within prokaryotic system like E.Coli