Final answer:
RNA polymerase attaches to the promoter of the gene, which is the specific nucleotide sequence that signals the initiation of transcription.
Step-by-step explanation:
The transcription enzyme, typically referred to as RNA polymerase, first attaches to the promoter of the gene. The promoter is a specific sequence of nucleotides located upstream of the gene that functions as a signal for RNA polymerase to bind and initiate transcription. This sequence is crucial as it not only triggers the start of transcription but also determines the frequency with which a gene is transcribed. The promoter region can vary in length and complexity, accommodating the binding of various transcription factors that regulate gene expression.
In prokaryotes, common promoter sequences are found at the -10 and -35 positions upstream of the initiation site. The -10 sequence, known as the TATA box (TATAAT), is particularly important for promoter recognition. In eukaryotes, the promoter sequences are typically larger and more complex but also contain a TATA box. The binding of RNA polymerase to the promoter marks the beginning of the transcription process.