Hi Drew,

The terminator prevents the generation of very long transcripts which would encode several peptides. Usually, you are interested in expressing one gene of interest per plasmid controlled by a specific promoter. Since you are not interested in regulating the expression of e.g. the antibiotic resistance gene by the very same promoter, it is useful to insert a terminator downstream of your gene of interest. Double terminators can be used to increase the likelihood of transcription termination, because transcriptional regulation is never perfect.

Nevertheless, it might be technically a little bit more challenging to clone a plasmid including a transcription terminator compared to the same plasmid without a terminator. Issues are caused by the inherent sequence properties of the terminator. It folds secondary structures leading to trouble e.g. in gene synthesis.

yes I agree to Boas Pucker answer , it prevents the generation of very long transcripts

Hi Drew, All the above but also the structure of the terminator can stabilize the RNA molecule and lengthen its half life, leading to better protein expression.

Boas Pucker have you ever clone a plasmid with the transcriptional terminator sequence? Any advices? Thanks