基于FlowSeq技术对大肠杆菌内源性终止子构效关系的研究

he rho factor-independent terminator (intrinsic terminator) relies on its hairpin and the U-tract structure to promote the transcript termination, which can effectively avoid the read-through of downstream gene transcription and improve the utilization of RNA polymerase efficiency, thereby facilitates the regulation of gene expression.It is important to understand the key features of terminators associated with terminating efficiency, besides it is not clear if the terminator affects the upstream gene expression. Therefore, it is important to correlate the genoype and phynotype of terminator based on vast terminator date set. In this study, we first characterized the expression of the upstream and downstream gene under the regulation of 20 sequences with and without terminator structural features, and compared the effects of these two types of sequences on gene expression. Next, we constructed a terminator mutation library and collected the geno/pheno-type information of 808 terminator sequences with FlowSeq technology. 225 terminator sequences with more than 5 reads detected showed that under the regulation of terminator, the expression of upstream and downstream genes showed an inversely proportional trend. Finally, we divided the strong and weak terminators in the terminator mutation library,and the discrimination features including both sequence characteristics and thermodynamic parameterswere conducted, and the result showed the stem length and the U content of the U-tract region in the terminator have an important impact on the strength of the terminator. The informaton obtained here can be applied in the rational desgin of terminators for accruate gene expression.