Editing Promoter (genetics) (section)

== Binding ==
{{See also|Promoter activity}}

The initiation of the transcription is a multistep sequential process that involves several mechanisms: promoter location, initial reversible binding of RNA polymerase, conformational changes in RNA polymerase, conformational changes in DNA, binding of nucleoside triphosphate  (NTP) to the functional RNA polymerase-promoter complex,  and nonproductive and productive initiation of RNA synthesis.<ref>{{cite journal | vauthors = deHaseth PL, Zupancic ML, Record MT | title = RNA polymerase-promoter interactions: the comings and goings of RNA polymerase | journal = Journal of Bacteriology | volume = 180 | issue = 12 | pages = 3019–3025 | date = June 1998 | pmid = 9620948 | pmc = 107799 | doi = 10.1128/jb.180.12.3019-3025.1998 }}</ref><ref name=":0" />

The promoter binding process is crucial in the understanding of the process of gene expression. Tuning synthetic genetic systems relies on precisely engineered synthetic promoters with known levels of transcription rates.<ref name=":0" />

=== Location ===
Although RNA polymerase [[holoenzyme]] shows high affinity to non-specific sites of the DNA, this characteristic does not allow us to clarify the process of promoter location.<ref name="pmid3308887">{{cite journal | vauthors = Singer P, Wu CW | title = Promoter search by Escherichia coli RNA polymerase on a circular DNA template | journal = The Journal of Biological Chemistry | volume = 262 | issue = 29 | pages = 14178–14189 | date = October 1987 | pmid = 3308887 | doi = 10.1016/S0021-9258(18)47921-5 | doi-access = free }}</ref> This process of promoter location has been attributed to the structure of the holoenzyme to DNA and sigma 4 to DNA complexes.<ref>{{cite journal | vauthors = Borukhov S, Nudler E | title = RNA polymerase holoenzyme: structure, function and biological implications | journal = Current Opinion in Microbiology | volume = 6 | issue = 2 | pages = 93–100 | date = April 2003 | pmid = 12732296 | doi = 10.1016/s1369-5274(03)00036-5 }}</ref>