Final answer:
Cis-acting elements near regulatory elements within mRNA play a vital role in the transcription of adjacent genes. Enhancers can also affect transcription despite their distance from the gene. Transcription factors binding to these elements control gene expression through complex interactions with RNA polymerase and DNA structure.
Step-by-step explanation:
Elements that sit beside or near the regulatory element in question, which may fall within the translated region of mRNA, are known as cis-acting elements. These elements include transcription factor binding sites within the promoter region that regulate the transcription of neighbouring genes. Enhancers, in contrast, may be located at varying distances from the gene they regulate and function by looping back to interact with the gene's promoter to enhance transcription.
In eukaryotes, the regulation of transcription is a complex process involving multiple components. Transcription factors that bind to cis regulatory elements proximal to or distal from the gene's promoter are key. These regulatory proteins can act as activators, facilitating the interaction between RNA polymerase and the promoter, or as repressors, to impede transcription. Additional elements like enhancers can have a significant impact but are not limited by proximity to the gene they influence.
Thus, the elements being discussed may play various roles in controlling gene expression depending on their position relative to the promoter and the specific transcription factors that bind to them. Both proximal and distal regulatory sequences, as well as the DNA's physical configuration, contribute to fine-tuning the transcriptional response to cellular signals and environmental cues.