Final answer:
The leader region of a gene can form different conformations through the process of alternative splicing, which allows for various proteins to be encoded by the same gene. Transcription factors regulate gene expression by influencing RNA polymerase activity, and enhancer regions facilitate these interactions. DNA supercoiling is also a fundamental aspect of gene expression but is not the correct answer in this case.
Step-by-step explanation:
The leader region can form different conformations via alternative splicing. Alternative splicing is a process that allows a single gene to code for multiple proteins. In this process, different segments, or exons, of a pre-mRNA are joined or spliced together in different combinations, thus enabling the production of different protein isoforms from the same DNA sequence.
Transcription factors play a critical role in gene expression by binding to enhancer regions and affecting the transcription of genes, potentially across large distances within the DNA due to DNA bending. These enhancers serve as binding sequences for transcription factors, which can either enhance or repress the transcription of specific genes when interacting with the RNA polymerase.