The
DNA region, usually upsteam to the coding
sequence of a
gene or
operon, which binds and directs
RNA polymerase to the correct transcriptional start site and thus permits the initation
of
transcription.
Source:
PAC, 1992, 64, 143
(Glossary for chemists of terms used in biotechnology (IUPAC Recommendations 1992))
on page 163