Question

Wedel et al Science (1990) 248:486-489] studied how postive acting transcription factors work by nlyzing B the requirements for binding in vitro (in a test tube) of RNA polymerase to the position near the start of transcription. Two situations were examined (shown at right). In the first, a plasmid carrying the binding site (B) for a positive acting transcriptional regulator was mixed with a separate plasmid carrying the transcriptional start site (TSS) plus 32 bases upstream. TSS TSS In the second, these two plasmids were linked together like in a chain). The authors added RNA polymerase, the positive acting transcriptional regulator. plus other necessary components to the two plasmids and measured transcription. They found that transcription was significantly higher when the plasmids were linked than when they were not. What does this result say about what is required for binding sites to enhance transcription

Please answer the question in its entirety, including explanations.

Answer 1

The binding sites help to recruit the different regulators that regulate (upregulate or downregulate) the gene expression or transcription. Here, in the linked plasmid, the binding sites may recruit some other proteins which enhance the gene expression and therefore the linked plasmid have more transcription than the separate plasmid.