I'm confused...
During transcription, in
initiation, the
RNA polymerase (not DNA polymerase. DNA polymerase is used in DNA replication) attaches to the promoter region of the DNA and begins to unzip the DNA into two strands.
From Wikipedia:
An
operon is a functioning unit of key
nucleotide sequences of
DNA including an
operator, a common
promoter, and one or more
structural genes, which is controlled as a unit to produce
messenger RNA (mRNA), in the process of
transcription by an RNA polymerase.
perons occur primarily in
prokaryotes but also in some
eukaryotes, including
nematodes. An operon is made up of several
structural genes arranged under a common
promoter and regulated by a common
operator. It is a set of adjacent structural genes whose mRNA is synthesized in one piece, plus the adjacent regulatory signals that affect transcription of the structural genes.5
[1] The regulators of a given operon, including
repressors,
corepressors, and
activators, are not necessarily coded for by that operon. The location and condition of the regulators,
promoter,
operator and structural DNA sequences can determine the effects of common mutations. The first operon to be described was the lac-operon in
Escherichia coli.
[2]
Operons are related to
regulons and
stimulons. Whereas operons contain a set of genes regulated by the same
operator, regulons contain a set of genes under regulation by a single regulatory protein, and stimulons contain a set of genes under regulation by a single cell stimulus.